Wait so do you use great people to tech, as in bulbing techs? Is that the focus of a SE?
you can, but the GS's gained can also be settled into your oxford city to create an SSE [super specialist economy], where the vast majority of your science output is from that city. Combine that city with a national epic, GS built academy, high food yield to support as many scientists as possible, the GL [if you can build it], and you'll be surprised how many beakers you can generate. A settled GS under representation nets +9 raw beakers before modifiers.
So how you use your GS's is up to you, personally, I'll usually bulb only if it's a critical tech in the early game [philosophy, paper, education are most prominent in my mind], and bulb more often in the later game, but this is because I'm still more inclined to research things myself rather than trade for them, while stealing techs to back fill.
Biology is great for the SE, but so is sushi and cereal mills.
Furthermore, if you're running an SSE more often than not, you'll come to a crunch point where you have to switch out of slavery into caste to maximize the potential of that city. In a traditional SE it's not as important as you can often get by on the scientist slots available via buildings, but the switch from slavery to caste can be tricky to time without practice.
The culture slider becomes your way of adapting to emancipation, which is why it's often regarded that creative is a top tier SE trait, cheap theatres and libraries. And why Justinian's UB is great in an SE as well [double happiness theatres]
Industrious is also a great SE trait as it gives you a fighting chance at the 'myds without stone, which essentially makes the SE most viable anyway.
Spiritual is another great SE trait as it can allow you to flip between slavery and caste, as well as pacifism and theocracy when cycling between production and science.
On hybrid economies:
Because your cities are food rich, commerce poor, you will need some kind of economic-based cities to support a large empire. Whether this be with with a few cottage cities, or a hybrid hammer-based [a very nice option with caste workshops in the mid-late game] or some combination of, something will have to be generating money for you. Just remember, that if you are in an SE, you're science slider will be running much lower and the cottage cities will benefit most from markets, banks, and grocers, so your cities become more specialized with a clear distinction between wealth generating and science generating.
Pros of an SE:
-Can expand faster, as you're less worried about keeping your science slider up in the early game because you're offsetting the difference with scientists, and can delay the building of pure financial cities longer because of it.
-More specialized cities mean less building per city.
-It tends to 'take off' faster than a CE, because each scientist is of larger start up raw beakers than most cottages.
-More GS's mean more bulbing options, or the SSE city [consequently better trade bait, or even more beakers]
-flexible in productive capabilities and cycling through war time production [setting those Specialists to work mines and workshops, and peaceful scientific research
-EDIT-
-easier to rebuild after being pillaged
Cons:
-No HR to grow your cities, so happiness can become a factor
-Loses out in raw beaker output to fully mature cottages
-emancipation hurts every SE in time
-micromanagement intensive, and the city governor often doesn't do a good job
-no slavery in caste.
Personally, I prefer an SE to a CE, but I'm finding it's much more situational than a CE. It's great for warring, and it's rare that I'll go for any other victory than domination or cultural with it, because enduring the late-years for a time or space victory is painful to watch.