So I wrote my official review for FangirlNation. Short version: I liked it lots. Longer version: here. I have to say, it was a hard review to write because I really liked it, and I also really wanted to just say "Groot! Groot! Groot!" Yes, the things I say about the ensemble are true: It's a very good, very balanced team movie. But--Groot's a favorite character of mine in teh books, and they did a fantastic job on him in the movie.
Also, now Marvel is releasing little making-of clips. Here's a bit on costume and props: