Do you know what? I'm going to say AW is worse than CI.
Both cost the same to build (aside - AW coming a bit later means hammers are more available due to workshops and higher happy caps). Both are on the same tech ladder. Both have a mediocre effect.
CI means newly captured cities have some defence just for existing without having to whip Walls or run CS to border pop. That's not much for 500 hammers, but it's better than +1 hammer per Priest. If I want hammers at expense of population growth, I'll mine. If my need for GPT is so great I'm running specialists, I'll run CS merchants. I run Priests for one reason: to generate GP's. If I'm desperate enough for GPP that Wonders are an attractive source, I can get CI earlier than AW. Sure, AW lets me shotgun the GP with three Priests, but once I've bulbed Theo or built a Shrine, what am I going to use those slots for? Extra GPs after that are pretty much GA-fodder, most other people are more useful.
Also - does the +25% per city influence the Power graph at all? If it can scarecrow Monty et al, then the 'just build axes instead' wisdom has to bear in mind upkeep on the units - especially if we're running Pacifism.)