I rented and re-watched this movie (for the second time), and then listened to Whedon's commentary track. I wasn't blown away initially, and repeated viewings didn't really improve things, though obviously I could better digest the whole thing. Like Evilface, I think this was a good movie, but not great. I think part of it is Whedon's schtick, while refreshing and cool once upon a time (the time of Buffy and Firefly, anyway) gets a bit predictable after awhile. The James Gunn style humor felt much fresher, the fights in Winter Soldier felt more intense, and the drama. . .well, the Marvel Studios-verse doesn't hang its hat on the dramatic aspect, fortunately for everyone.
If/when RDJ Stark and Evans Cap start taking a back seat, I think that could be a good thing. At least for awhile. Would love to see the focus shift to Captain Marvel, Spidey, or maybe even (crosses fingers and whispers prayers to make this happen) Nighthawk! But I did enjoy the movie about the same as I did at the theater, so there wasn't a drop off here for me, as there was when I saw Thor 2, Winter Soldier, and some others.
One thing that I didn't notice that Whedon brought up on the commentary was that Maria Hill is wearing Cap's jacket in one scene. And I thought that was peculiar.