Yeah, I agree with you about the persona thing. The main character doesn't even really look like the P3 MC outside of that one pic that was going around. I was actually expecting the games to be a lot more similar.
The game is fun enough with my only complaint being there is quite a bit of backtracking for some of the sidequests. A lot of sidequests have you going deeper into previous dungeons than the story brings you. I don't mind that and you normally complete them as you try to fully explore the dungeon. There is a certain NPC however that gives you a quest to find certain items in the dungeon. They are usually in floors you have already completed and are not visible on the map. I ended up just going to gamefaqs for the co-ordinates every time she had a quest.