P3 got me back into JRPGs, too.
It takes a different approach from P4 with its story and characters. It took me a while to really get into it, but when it does, it is really good. I would definitely give it some time. At first i wasn't really sold on the game. The characters start off kinda "cold" compared to P4. It takes time before they open up and feel comfortable around you. It's a more gradual process than P4. It's realistic for the circumstances that they are kinda distant at first, but on my first playthrough, I remember feeling a little disconnected. Unlike P4, SEES all have had a really tough background, so they have more of a guard up. But they really do get a lot of character development and about several game months in, everyone in SEES really lightens up and feels more close. P4 has more humorous moments and happy fun times scenes, but P3 still has its fair share and IMO they aren't quite as over-the-top as most of P4's (camping trip, beauty pageant, hot springs).
Once the story really got rolling, it is very interesting.