Are the only real differences the starting dungeon and deciding which char is in charge and who's an NPC or is there more going on?

Maybe some wholly different dialogue in dungeons or character exclusive strolls?

I'm getting near the end and would really like to know if playing this a second time is worth it.

Yes. The whole game is more P3 or more P4 heavy (the setting and so forth), depending on the choice. Especially the first 5 hours of the game.

But I don't know if the dialogue or strolls are different... I ready that online, I'm still in the middle of my first playthrough.

@twolines: @sessh: I kinda wish they would of given both characters their voices versus just the one you didn't pick. I am loving the game though. Is anyone in the GB crew is playing it?

I hope that's the case. Actually, I hope that the two sides are either different enough to warrant a second full playthrough or converge enough that once is enough for both sides. I would be kind of bummed if there were enough big differences to feel like you're missing out, but not enough to fill a second 20/30/40+ hour (or however long the game is) playthrough.

And I'm also really torn about whether to pick SEES or the Investigation Team. I was initially 100% on board for P4, but the cast of P3 is finally starting to grow on me as I play through P3:FES. Even Junpei. Well, maybe not Junpei.

I ended up going with P3 for 2 reasons, 1 philosophical and 1 practical. The first reason is that I never personally played P4, I only watched the Endurance Run. I have played P3 though (or am in the process of doing so). Charlie Tunoku is Vinny and Jeff's character, but Johnny Tunoku (my 100% canonically named P3 protagonist who just happens to be Charlie's cousin) is my character.

The second, more practical reason is that the game forces you to use your "main" persona at all times. You can have subs to grant extra skills and boost stats and whatever, but as I understand it, you're always going to be using either Orpheus or Izanagi. I plan on using Akihiko and/or Kanji in my main party, so having a third lightning based character would be redundant. By the same token, I don't plan on using Yukiko or Junpei all that much, so Orpheus is the only one with fire skills (except for Koromaru, I guess :3 )