Here's the way I look at cottages vs. specialists:
In the early game, unless I have the pyramids and the choice to go with rep, then there's nothing to be gained, per se, by mandating all of one's tiles be going towards one type of "economy" or the other. You don't have the civics to boost either one, so the decision of whether to run specialists or cottages comes down to a city-by-city basis, at least until the printing press/liberalism/constitution, when you can benefit from actually gearing your whole civ around a certain civic (and thus around a certain economy).
So, in the early game, I'll run specialists where I have surplus food and can't grow anymore due to the happy cap, and I'll grow cottages in cities that don't have a lot of surplus food and need a citizen working every tile (preferably grassland cottages) in order to grow more quickly.
With specialists, one definitely needs to not just consider the beakers one gets, but the GPP points as well.
Consider: the first great person costs 100 GPP and, if it's a scientist, can potentially yield over 1500 beakers from bulbing, right? (In fact, (1500 + (3*pop)) if I recall correctly). Now, of course, often one does not used this full amount in bulbing techs, except for techs like education which cost more than 1 scientist to bulb. But let's assume we get ~ 1500 beakers from a scientist bulb on average.
So for that first great scientist, that's over 15 beakers per GPP. So a scientist specialist in that first city to produce a GS that is seemingly producing "only" 3 beakers + 3 GPP per turn is actually producing 3 + 3*15 = 48 beakers per turn! Assuming we are feeding a scientist with two farms, then that's 48/3 = 16 beakers per citizen, and 48/2 = 24 beakers/tile.
After the first GS is born, the next one costs 200 GPP, and gives the same 1500 beakers. So that's 7.5 beakers per GPP. So the scientist specialists at that 2nd city are producing 3 + 3*7.5 = 25.5 beakers per turn. That's 25.5/3 = 8.5 beakers per citizen, and 25.5/2 = 12.75 beakers/tile.
For the third city, its GS will cost 300 GPP. 5 beakers per GPP. 3 + 3*5 = 18 beakers/turn. 18/3 = 6 beakers/citizen. 18/2 = 9 beakers/tile.
For the fourth city, its GS will cost 400 GPP. 3.75 beakers per GPP. 3 + 3*3.75 = 14.25 beakers/turn. 14.25/3 = 4.75 beakers/citizen. 14.25/2 = 7.125 beakers/tile.
For the fifth city, its GS will cost 500 GPP. 3 beakers per GPP. 3 + 3*3 = 12 beakers/turn. 12/3 = 4 beakers/citizen. 12/2 = 6 beakers/tile.
So, by the fifth city, cottages (up to 4 beakers/citizen and 4 beakers/food-neutral-tile if grassland) start to become competitive. So it only makes sense to build a library and run two scientists in about 5 cities. If you have more cities than that, cottage the rest. (And note: this is independent of map size, total # of cities, etc. So a predominantly specialist economy in the early game is going to make more sense on a small map than on a large one (where you will have many cities beyond the fifth city that will be better off working cottages)).
And keep in mind, if one is bulbing stuff like philosophy, then you can cut these calculations in half (because you're only getting like 750 beakers from each bulb) and so it wouldn't make sense to run 2 scientist specialists beyond a third city.
Also, these calculations suggest that if a city is never going to produce another great person, then (non-rep-boosted) scientist specialists give really crappy yields. So if it is at all possible (meaning, if happy caps allow), after a city running 2 scientists has produced its GP, then it is a good idea for that city to stop running 2 scientists and start doing something else, because those GPP are going to end up equaling 0 beakers, and the only thing you'll be getting is 3 beakers/turn, or 3/3 = 1 beaker per citizen, or 3/2 = 1.5 beakers per tile.
Finally, these calculations suggest that whether one gets the pyramids or not is a trivial factor in the decision of how many pairs of scientists to run. Whether that 1st city gives 48 beakers/turn or 51 beakers/turn doesn't really matter a whole lot.
On the other hand, the philosophical trait really changes these calculations dramatically by making each scientist specialist give twice as many GPP, and thus almost twice as many beakers, in effect. For that city producing the first GS, a scientist specialist will actually produce 3 + 6*15 = 93 beakers/turn!!! (And, whoopdie-do, 6 + 6*15 = 96 beakers/turn if you bothered to chop out the pyramids).
The same thing applies to pacifism as to the philosophical trait (and halfway so to the parthenon). So according to these calculations, the really key wonder to an early game specialist economy is not the pyramids, but the parthenon, because the scientists in the city producing the first GS will produce 3 + 4.5*15 = 70.5 beakers/turn, vs. 6 + 3*15 = 51 beakers/turn if you had the pyramids but not the parthenon.
In the early game, unless I have the pyramids and the choice to go with rep, then there's nothing to be gained, per se, by mandating all of one's tiles be going towards one type of "economy" or the other. You don't have the civics to boost either one, so the decision of whether to run specialists or cottages comes down to a city-by-city basis, at least until the printing press/liberalism/constitution, when you can benefit from actually gearing your whole civ around a certain civic (and thus around a certain economy).
So, in the early game, I'll run specialists where I have surplus food and can't grow anymore due to the happy cap, and I'll grow cottages in cities that don't have a lot of surplus food and need a citizen working every tile (preferably grassland cottages) in order to grow more quickly.
With specialists, one definitely needs to not just consider the beakers one gets, but the GPP points as well.
Consider: the first great person costs 100 GPP and, if it's a scientist, can potentially yield over 1500 beakers from bulbing, right? (In fact, (1500 + (3*pop)) if I recall correctly). Now, of course, often one does not used this full amount in bulbing techs, except for techs like education which cost more than 1 scientist to bulb. But let's assume we get ~ 1500 beakers from a scientist bulb on average.
So for that first great scientist, that's over 15 beakers per GPP. So a scientist specialist in that first city to produce a GS that is seemingly producing "only" 3 beakers + 3 GPP per turn is actually producing 3 + 3*15 = 48 beakers per turn! Assuming we are feeding a scientist with two farms, then that's 48/3 = 16 beakers per citizen, and 48/2 = 24 beakers/tile.
After the first GS is born, the next one costs 200 GPP, and gives the same 1500 beakers. So that's 7.5 beakers per GPP. So the scientist specialists at that 2nd city are producing 3 + 3*7.5 = 25.5 beakers per turn. That's 25.5/3 = 8.5 beakers per citizen, and 25.5/2 = 12.75 beakers/tile.
For the third city, its GS will cost 300 GPP. 5 beakers per GPP. 3 + 3*5 = 18 beakers/turn. 18/3 = 6 beakers/citizen. 18/2 = 9 beakers/tile.
For the fourth city, its GS will cost 400 GPP. 3.75 beakers per GPP. 3 + 3*3.75 = 14.25 beakers/turn. 14.25/3 = 4.75 beakers/citizen. 14.25/2 = 7.125 beakers/tile.
For the fifth city, its GS will cost 500 GPP. 3 beakers per GPP. 3 + 3*3 = 12 beakers/turn. 12/3 = 4 beakers/citizen. 12/2 = 6 beakers/tile.
So, by the fifth city, cottages (up to 4 beakers/citizen and 4 beakers/food-neutral-tile if grassland) start to become competitive. So it only makes sense to build a library and run two scientists in about 5 cities. If you have more cities than that, cottage the rest. (And note: this is independent of map size, total # of cities, etc. So a predominantly specialist economy in the early game is going to make more sense on a small map than on a large one (where you will have many cities beyond the fifth city that will be better off working cottages)).
And keep in mind, if one is bulbing stuff like philosophy, then you can cut these calculations in half (because you're only getting like 750 beakers from each bulb) and so it wouldn't make sense to run 2 scientist specialists beyond a third city.
Also, these calculations suggest that if a city is never going to produce another great person, then (non-rep-boosted) scientist specialists give really crappy yields. So if it is at all possible (meaning, if happy caps allow), after a city running 2 scientists has produced its GP, then it is a good idea for that city to stop running 2 scientists and start doing something else, because those GPP are going to end up equaling 0 beakers, and the only thing you'll be getting is 3 beakers/turn, or 3/3 = 1 beaker per citizen, or 3/2 = 1.5 beakers per tile.
Finally, these calculations suggest that whether one gets the pyramids or not is a trivial factor in the decision of how many pairs of scientists to run. Whether that 1st city gives 48 beakers/turn or 51 beakers/turn doesn't really matter a whole lot.
On the other hand, the philosophical trait really changes these calculations dramatically by making each scientist specialist give twice as many GPP, and thus almost twice as many beakers, in effect. For that city producing the first GS, a scientist specialist will actually produce 3 + 6*15 = 93 beakers/turn!!! (And, whoopdie-do, 6 + 6*15 = 96 beakers/turn if you bothered to chop out the pyramids).
The same thing applies to pacifism as to the philosophical trait (and halfway so to the parthenon). So according to these calculations, the really key wonder to an early game specialist economy is not the pyramids, but the parthenon, because the scientists in the city producing the first GS will produce 3 + 4.5*15 = 70.5 beakers/turn, vs. 6 + 3*15 = 51 beakers/turn if you had the pyramids but not the parthenon.
is worth much more than 1
). If you don't run slavery for easy conversion, there are still workshops and hills which you might otherwise leave idle. Hammers can be turned into commercy things by building them but that's usually a horrible waste. Failure cash if I have the wonder resource is the only direct conversion I sometimes consider worthwhile.
(we need to gain one since yields of the hamlet add up to 4 rather than 5) is possible by using awful conversion mechanics. I'd go so far and say that 1
and 
in the middle of this all?
if it is fair game to pretend that specs don't give GPP, it is also fair game to compare specs with any of the states of the cottage development ( in fact IMHO it is even more fair )
, so I don't see your point here ) . But again you can't assume modifiers for beakers and no modifiers for espionage usage ( or vice versa ) for sake of fairness. My point with that text was to point that.
. These words are better than any I can write. His point about hybrids is most pertinent to this topic. They are generally inefficient, either the cottages lose out or the specialists do, depending on the civics you'll be running in the middle and late game. If you go with cottage spam then the CE civics will make the most of your economy in the end game and so it makes sense to build more cottages where you have that choice. Without SE civics specialists will tend to be below par outside the GP farm where GPPs make up for the shortfall. If you follow the SE approach then any cottage will always be limited to 5 commerce by the end game civics and lose about 40% of its potential. In that case limiting the number of cottages and maximising the number of specialists will tend to improve the economy. Where you have choice in the matter it is generally it is better to move towards either one or the other end of the cottages - specialist spectrum and run the appropriate civics.
