Spammurabi said:
There are costs of running a cottage-heavy civilization- you have lower population and production than your neighbors. While you might enjoy a tech lead, your opponents will have far more units than you, and a smart (or merely aggressive) opponent will take advantage of your weakness. A balance between hammer and gold production must be maintained throughout the majority of the game, and retooling your entire economy to focus entirely on gold rushing requires a great number or worker turns and sacrificing production or food on your newly cottaged tiles.
Sorry Spammurabi but I don't agree with you. This is only personal experience but as I said in an earlier post, after "enacting" this strategy, my GNP AND power increased almost exponentially, whereas for the entire game up to that point both had only increased roughly linearly. Remember too that power is primarily dependent on unit number and strength. You have the impression that cash-rushing gives you a tech-lead but not more units. We are arguing that cash-rushing is a powerful strategy for buidling things (as implied by the strategy's name) - not for tech leads. Of course having lots of towns is also good for getting a tech-lead as well. Therein lies the key though. There doesn't appear to be any significant weakness to the strategy. You
don't have to sacrifice research to use this strategy effectively.
I don't agree either that the time of enacting the strategy requires a lot of worker turns. Hopefully you would already have many commerce cities that have focused on town growth. You would only have to change a few farms here and there to cottages, and some watermills etc. Leave your 3 or 4 best production cities with hammers obviously as you will need them for building projects or for building those first factories etc. If you have a GP factory it may be best to leave that alone but that's up to you.
As Roland noted, the cottages become better than workshops very quickly (after reaching village), meaning that as the towns grow, the benefit only gets larger. It is assumed you would have a stable enough empire to last 30 or so turns of reduced-production. The pay-off makes it worth it.
And you are correct that this is a late-game strategy, and as Roland noted we have all said that. But as a late-game strategy it is VERY POWERFUL. Note my opinions are for SP games as I have little experience with MP games.
It may be true you will have a lower population than a rival who focuses more on farms, but why does that matter? AFAIK population is only useful for scoring. Having 10 citizens work 10 farms is not more beneficial than having only 4 citizens work 4 towns. As long as you manage your improvements so as to maximise the number of towns you can work (which may mean building a farm or two here and there), population is not important. In other words, population in itself is not something that gives you any benefit, as you know, but population is only useful for what it can DO. Citizens that work only to increase the number of citizens is kind of like a viscious, pointless cycle, unless maybe you like pop-rushing.
If you are dubious about the strategy's effectiveness, at least try using it in one game. I was honestly surprised at how well it worked when I tried it, even having read about it already.