Though there were times when the dialogue and acting seemed strained and out-of-character, the humor in the writing and pace of the movie off-set it nicely. I saw it in 3D and I recommend as a 3D movie. The visual effects were spectacular as I expected from a Joss Whedon movie. I was a little disappointed that the only "romance" was an insinuated infatuation/"hero"-worship towards Captain America... (Oops! that hinted at a spoiler).
Basically, I'm giving it a massive "GOTTA SEE LIKE NOW!" I actually wanted to go back to the ticket sales and get another ticket to see it again right away.