It's funny that I really like this game but for some reason I haven't been playing it since I just got to Rise's level. I'm really not sure why, but I guess it's because there are other games that have me hooke at the moment rather than P4 despite those games probably not being as good as P4.
In comparison to the last game, I'm not sure if I'll like or more or less than it. While it definitely improves on the last game in terms of gameplay, I personally loved the last game for it's incredible story and its interesting method of telling it. P4 still has that element, and its story from what I've played of it thus far has been good, it's just that I'm not sure if it'll be as effective as the last game. After all, the flaws in the last game didn't really bother me much and coming into this one what I cared about the most was the story and characters.
The game is much more straightforward than P3. While you still have the choice of when you want to go there, you're required to beat each dungeon within a month and the dungeons in question are all about 10-20 floors each with a sub and main boss. Level grinding is still pretty much necessary in that if you ignore all your enemies while progressing through the levels, you're going to be screwed when you reach the boss. But it's not problematic because if you consistently kill enemies as you progress you should be strong enough to fight the boss.
Personally, what really improves combat is the fact you can control your teammates. Now you can ensure that they won't do anything stupid in combat and that you can now fight more strategically. Ths is great since this was a pretty big flaw in the last game and it ensures that you're less likely to be screwed over. However, this makes way for another problem in that you can't immediately retreat which makes doing so possibly pointless as either you're about to kill the enemy or they've killed you.
Comparing the battle system with the last game I'd say this game has improved on it thanks to the full team control. The retreating is a pain in the ass for sure, but it's passable.
Outside of combat, they definitely made it so that there's a lot more to do. From what I found thus far, none of the new activities hurt your social connections very much but none of them feel that significant. Though they are welcome additions to the game nonetheless.
All in all, it's a great game and fans of the last game will definitely love it and it definitely improves on the last games gameplay, but as I'm more concerned with the story than the gameplay when it comes to this game I'm not sure if I'll like it as much as I did the last.