Total playtime 48 hours. Like P4G, battles start off a bit tougher than other games but the difficulty starts to landslide after the halfway point once you start getting decent skills and skill cards- As in the final boss didn't even scratch me and the fight took like five minutes.
Personal game-breaking combo was Chie with setsunasamidaregeki and charge, with buffs. The final boss fight basically consisted of
Boss attacks: Miss miss 50 miss 30
Chie attacks: 600 1200 1200 600 600 600 1200 600
The final boss does have what looks like a pretty troublesome gimmick, but I killed him too fast for it to matter.
The writing was pretty decent, and the interaction between the P3 and P4 characters was basically what I wanted in P4U but didn't get. Plus there's actual character development. It feels really weird, though, because by the end it's suggested that Amada has forgiven Aragaki, which is of course completely out of place. Sure, they forget all the events of this game, but still. I went with the P4 route first though, so maybe the P3 ending handles this better.
And while the fights are easy, some of the dungeon gimmicks get almost up to Strange Journey levels of annoying. Nothing as bad as SJ's invisible wall conveyer belt mazes though. And of course nothing in the game even comes close to fucking Asuraroga.
But anyway yeah, it's pretty good.
The usual end-of-game stats:
Odin on the P3 protagonist is something of a tradition for me, as he's what I cleared P3 with the first time I played it.
Anyway, my strategy basically consisted of everyone casting buffs while Chie punches the boss to death. Simple but really, really, really effective.
Edit: Cleared the two post-game sidequests too.