I think the characters and overall story-line of this game is a bit better than P5R, but the QOL and game-play improvements in P5R make it the better game. If you don't mind the somewhat dated combat and relatively boring auto-generated dungeon design, I'd really recommend giving this game a try despite its age, especially if you liked any other Persona game. Most of my gripes with the game are simply when comparing the game to its sequel, which improved on an already excellent game in P4G.

Pros
+Fantastic story, especially if you haven't had any of the ending spoiled for you.
+Majority of social links are great.
+Great character cast. Compared to the Phantom Thieves, the Investigation Team feels much more like a group of friends and the various interactions throughout the game really fleshes them out as characters. I love the cast of P5R, but I think I might like P4G's cast a bit more.
+Game-play loop is still pretty good, even if its dated compared to P5R.
+Long game length. The game took me about 80 hours on my first play-through after completing all social links and getting to the True Golden ending.
+Many different endings.
+OST is amazing, especially in the later dungeons and the daytime themes.

Cons
-Not as much to do outside of social links. There is not as many side activities to do when compared to P5R, especially at night.
-Auto-generated dungeons are not as enjoyable to run through compared to P5R palaces.
-No baton pass and overall combat does not feel as satisfying as P5R.
-Some plot-holes, but nothing major.

Even today, I still think the game is a gem and worth playing, even after playing P5R first. A remake of the game with an updated combat system and palace-like dungeons would probably make it better than P5R tbh.

9.5/10