Two minor complaints
I really really enjoyed this movie. It is great fun to watch multiple times. I don't see any major flaws with it, though if I were to nitpick, I'd say two things bugged me a little bit.
1. Quicksilver/Pietro Maximoff casting: Personally I just didn't see Aaron Taylor Johnson as Quicksilver. He is a very good actor no doubt, but I found him to be a bit "buff" for a guy has has super speed/hyper metabolism. When someone says that a guy is really fast, the image that comes to my mind is someone like Bruce Lee, lean and sinewy. More fast muscle fibres than bulky muscles.
2. Friday casting: I was rather let down by the voice actress of Friday. Compared to JARVIS, Friday has very little to no character. She was a very forgettable "voice". Even the way she said certain lines just didn't fit in with the situation. Like the way she says, "Sokovia is going for a ride". Just didn't quite click with me.
Feel free to agree or disagree with my points and post your own little complaints.
"I'm the dude, playing a dude that's disguised as another dude".