It was really good. If you have been to any Comic or SciFi convention you'll relate to it. Heck, even if you haven't you'll get a good view of what its like.
It basically follows 5 different people who are going to the Con. Two guys who want their portfolio's reviewed, 1 girl and her costume team who've built elaborate Mass Effect costumes for the Masquerade competition, one guy who wants to propose to his girlfriend at the Con, and the owner of Mile High Comics for the vendor point of view.
All 5 experiences I found fascinating.
Especially interesting is the perspective you get from the owner of Mile High Comics and how comics have been pushed to the back now because of Hollywood. For example, they aren't allowed to use the loading dock because Lucasfilm owns it.
The hoops the guy who wants to propose has to go through to get the ring (at Comic Con) without his girlfriend seeing him is hilarious and very endearing.
Great cameo's & interviews with a host of stars who have always been fans - including Kevin Smith and Joss Whedon (both are Executive Producers).
And of course - it's not a Comic Con movie without Stan the Man Lee.

If it comes to your area - go see it. It was a lot of fun.