Ancién Regime is not very useful IMO. If you go for a cultural victory with 3-5 cities, it gives 6-10, not very useful at all. And it only lasts untill steam power. If I wanted to expand, I would pick a civ like Rome or Russia that was good at it. The Songhai's UB, the Mud Pyramid Mosque gives 4
per city that it is built it, with no maintenance cost! If you get Philosophy early and build these in all your cities, you will have an ability better than France. Another strategy is yo build monuments in all cities, adopt the Tradition policy that gives you a free culture building in each city, and you immediately have these in 4 cities.
Of course Songhai will produce better culture once it gets its Mud Pyramids up but you can't measure things like that. Building them costs time and hammers which France can use for other things. It is called opportunity cost and Frances UA has zero opportunity cost. Also since France starts getting extra culture from turn one they have accumulated quite lot of it once Songhai even thinks of building its UB. With liberty that advantage is even more clear when you get your free settler and worker so much faster. Sure Songhai may at some point in time catch Frances lead but that is not certain. In civilization early game advantage can snowball into a massive lead that others cannot hope to match. I'm not saying Songhai is a bad civ and in fact I really like their UB but you have to take costs into equation and its very hard to beat free stuff from turn one.
Also you should subtract 2 from the one you are down voting not 1. I corrected it again with my vote.
Ingenuity (Babylon) (21)
Ancien Régime (France) (19) +1
Great Andean Road (Inca) (20)
Achaemenic Legacy (Persia) (19)
The Glory of Rome (Rome) (16)
Siberian Riches (Russia) (15)
Sacrificial Captives (Aztecs) (15)
Father Governs Children (Siam) (14)
Population Growth (India) (13)
Bushido (Japan) (10) -2
Scholars of the Jade Hall (Korea) (13)
Art of War (China) (11)
Furor Teutonicus (Germany) (11)
Hellenic League (Greece) (10)
Viking Fury (Denmark) (7)
Monument Builders (Egypt) (4)
France: see above.
Japan: A lot of people seem to love Bushido but it really isn't that powerful in reality. It may save a unit here and there but you really can't leverage it properly as it way better to move wounded units into back ranks to heal than risk losing them even with Bushido. It is great ability for the retarted AIs but human players should be able save their units.