I would hope the AI is smarter on crysis; it is a much newer game. I think they are equally tactical; farcry even moreso I think because you have to conserve your health in farcry whereas you don’t in crysis (since it regenerates). I agree that the environment does change in Crysis but that alone doesn’t make it completely different from FarCry.
BTW, I HAVE played the demo, which is why I have such a strong opinion on the matter. And I just recently played some of farcry so I do know what I am talking about.