monkeyskin
Refugee
First, I'll acknowledge that Joseph Gordon Levitt is a better actor. He's hard not to like in 500 Days. But Jesse Eisenberg also perfectly nailed the awkwardness of his character (in a way that I think surpasses what someone like Michael Cera would have done with it), and I was cringing through a good portion of the film because of it. I consider this comparison a bit of a wash because of the different things they were aiming for.
And while I'm a big fan of THE DESCH!, I have to refer to what Lance posted and say that Stewart is a VERY talented actress who hints at depths that I really haven't seen from Zooey (maybe with the exception of her work in All The Real Girls). I think she gives a significantly better performance.
As for the humor, I'm pretty sure I laughed more during Adventureland. 500 Days was structurally more creative (which was your third point), but I don't know that the jokes or funny moments were overall better. Obviously we're talking about two different films here; we're not talking simply about two rom-coms directed at young people. One was trying to do something different with the genre, and I applaud its efforts in that regard. Adventureland was, as you say, more conventional, but gave us something very truthful that you don't often find in these types of films. Also, I'd add that because 500 Days is trying to stand out, things like Gordon-Levitt's VERY conventional (not to mention obvious) speech at the greeting card company ring false. And I'd still love to know where there's a karaoke bar in downtown L.A. where you can sing The Pixies.
Lastly, the music. If you consider what was used in Adventureland, yes, there's Lou Reed/VU material that isn't from the time period. But MOST of that soundtrack was. With 500 Days, it seemed that the music that tended to be highlighted was stuff made in the 80's, when the main characters (who appear to be somewhat recent college grads, maybe 23-25) were either not even born yet, or only a few years old. It's as if the screenwriter wanted all the music he listened to when he was younger to be in it, and forced those tastes on that characters. It's not as if there are no people nowadays who are into The Smiths, but I didn't get a sense that most of this music was from THEIR lives.
Jesse certainly nails his character, and after seeing him previously in Roger Dodger and The Squid and the Whale I'm most pleased to see his profile on the up. I'll agree though that the comparison is a bit moot as JGL had so much more to work with in terms of story and arc, but then again for me that's another plus for (500).
And yes Adventureland was more focussed (as LMP says, more of a coming of age story) and truthful to that particular age, but it still falls back on guy likes girl, both screw around on each other a bit, guy finds out about girl's misdemenours right after she's sworn them off due to her love for him, eventual reconcilliation. Bit flat really. Maybe I prefer (500) because they don't live happilly ever after and you can't force love with even the most romantic gesture. That to me is more honest, as well as the expectation / reality scene. I've mentioned this before but it really is one of the most effective relationship scenes I've watched in a long time. Who hasn't been there? Yes there were cliched moments but then so do most films.
I'll concede on the music, the probable character ages you brought up is something I hadn't considered. But I bet if you asked around in this forum you'd find a lot of guys and gals the same age with the same tastes.
But I love boths films, so it's all good.