It's hard for me to pick a clear winner, although my favorite to play is the Kavithan Protectorate. If I had to pick best as in strongest I'd pick Elodie, barely.
ARC - Assuming NOT using the establish network spam. Since getting to steal science doesn't take long at all and steal tech isn't that far behind, I'll approximate this UA to +33% science from covert ops. Pretty good. I lack the knowledge of which building quests give extra spies, which would help me evaluate this better.
PAC - I find the wonder bonus underwhelming. I rarely build wonders and even more rarely lose them to the AI. The worker bonus is okay, but mostly I think of this ability as meaning you have to build fewer workers. Not that big a deal.
PAU - Garbage
KP - Shaving ~6 turns getting a new city up is nice. Not all tiles are created equal, so larger borders means the tiles you work are better quality. If your borders bump up against the AI, with KP more of the land will be on your side. A good UA, not the strongest.
Brasilia - Garbage
Franco-Iberia - This takes good planning to really get the most out of, but even if you just pick the tech when you happen to hit virtue 10/20/30 the free tech is still powerful. A solid UA. 2 free techs a game is a good estimate I think.
Polystralia - It isn't a secret on these boards that trade routes are crazy good. If you use the bonus two on external routes, which I usually do, this is about +30 energy and +20 science per turn once you're in the midgame if you have a coastal capital.
SF - The free tech at a time of your choosing seems to be a crucial part of a couple different strategies I've read about. Such strategies really don't fit my playstyle though. Choosing when to get a free tech is nice, but I don't think it can beat Elodie who can get two free techs out in an average game. The 20% bonus to satellite time really needs reworked, especially as the increased time makes several satellites weaker (miasma repulser/condenser, weather controller, orbital fabricator).
ARC - Assuming NOT using the establish network spam. Since getting to steal science doesn't take long at all and steal tech isn't that far behind, I'll approximate this UA to +33% science from covert ops. Pretty good. I lack the knowledge of which building quests give extra spies, which would help me evaluate this better.
PAC - I find the wonder bonus underwhelming. I rarely build wonders and even more rarely lose them to the AI. The worker bonus is okay, but mostly I think of this ability as meaning you have to build fewer workers. Not that big a deal.
PAU - Garbage
KP - Shaving ~6 turns getting a new city up is nice. Not all tiles are created equal, so larger borders means the tiles you work are better quality. If your borders bump up against the AI, with KP more of the land will be on your side. A good UA, not the strongest.
Brasilia - Garbage
Franco-Iberia - This takes good planning to really get the most out of, but even if you just pick the tech when you happen to hit virtue 10/20/30 the free tech is still powerful. A solid UA. 2 free techs a game is a good estimate I think.
Polystralia - It isn't a secret on these boards that trade routes are crazy good. If you use the bonus two on external routes, which I usually do, this is about +30 energy and +20 science per turn once you're in the midgame if you have a coastal capital.
SF - The free tech at a time of your choosing seems to be a crucial part of a couple different strategies I've read about. Such strategies really don't fit my playstyle though. Choosing when to get a free tech is nice, but I don't think it can beat Elodie who can get two free techs out in an average game. The 20% bonus to satellite time really needs reworked, especially as the increased time makes several satellites weaker (miasma repulser/condenser, weather controller, orbital fabricator).