I started up a New Game + because, gosh darn, I only maxed eight social links, and three of those were automatic. I beat the second dungeon in one in-game day and I've already accomplished more than I did in the first playthrough.
Speaking of which, after beating the second dungeon boss I realized some stuff:
[spoiler]First, I figured out how Kanji's persona and shadow looked similar. Every other character's persona looked like their shadow, except Kanji's I thought. Then it hit me: Kanji's shadow is a half black and half white giant that carries giant clubs shaped like Mars Symbols, and his persona is a black giant with a white skeleton that carries a lightning bolt-shaped club. Seems obvious in hindsight.
This got me to figure out the meaning behind the persona evolutions that each character goes through if you max their S. Link. Almost every character's starting persona looks like a Power Ranger -- a Japanese children's super hero. When their personas evolve, they don't look terribly different, but they lose the Kamen Rider look. That's obviously a metaphor for growing up. The exception is Kanji's: if anything, his evolved persona looks even more childish. I'm pretty sure that's a metaphor for getting in touch with his softer side. I don't know, I didn't finish his S. Link.
Also: the Fool and the Judgment arcana represent the main character's Social Link with himself. I know it says it's his S. Link with SEES or the Investigation Team or whatever, but he's the leader of those groups. He identifies himself as the leader, and it's everybody's trust in him that makes him grow as a person as opposed to the way it goes for the other S. Links.[/spoiler]