3's is disjointed, you run around, people spout off exposition but you're not directly involved, then shit goes down and Tartarus shows up. It's not bad, but it's quick and gets you into the game. I like the smooth jazz, but aside from BABYBABYBABYBABYBABYBABYBABYBABY and Kimi no Kioku there isn't a hook there (I like Joy though, best home theme).
4's just takes waaaaaaaaay too long. I appreciate a slow burn, but that shit is ridiculous. It's legitimately 3 hours before you're actually allowed to play the game. Obviously the best soundtrack. All the ambient themes are great, only issue is the zone themes because dear god they get repetitive fast. But the actual songs are fine.
I just like how 5 throws you in and immediately you're allowed to wander. You don't do stuff right away, but you get a feel for everything and get to play around a bit before you hit the dungeon which only takes about an hour instead of 3. Plus having an actual nemesis to fight instead of "find Yukiko" while not as inter-personal, makes you a little more invested rather than "find this girl you've known for exactly 30 minutes.