About the only thing that's really a problem with the AI is that they don't quite heal as frequently as you'd like them to and have a tendency to debuff enemies rather than straight out attack them when it's kind of pointless. Fortunately in later levels your protag can become so bloody broken that this isn't really an issue so long as you don't mind having to play the supporting role every now and again in battles.80Maxwell08 said:Well did you find the AI a problem? Since I can put up with some AI problems if the cutscenes are important. I don't really like things being edited out.
As for the differing versions, only P3P has the female protagonist option, which allows you to change the story in minor ways and lets you woo (most of) the lads. As previously mentioned, some of the cutscenes have been taken out due to the hardware in question which can take away from the atmosphere, especially if you've played both versions, but overall if you didn't know, you'd never miss them.
P3: FES has the Answer which is the game's Epilogue, all of the cutscenes and generally is less painful to play for prolonged periods of time. (I got such massive handcramps on P3P.)
Overall if you have to pick one and aren't playing because you want a JRPG dating-sim (which is more of a sidequest portion of the game rather than a serious "must complete!" requirement) I'd say take FES. It's more comprehensive, has more material and any flaws it might have in comparison against P3P aren't massive enough to get in the way of enjoyment of the game.
Just as a friendly tip though, if you don't like possessive and extremely sensitive girls, do not go for Yukari. (Go for Fuuka. Fuuuuuuuuuka~)