Watchable. Should've been better, though.
James Spader - Couldn't have been a better choice for Ultron. Excellent!
Elizabeth Olsen (Scarlet Witch) - Bad acting. Really bad.
Captain America - Waste as always. This guy is boring.
Nick Fury, War Machine, Maria Hill - Waste
Bruce Banner - Pretty ok, but in the sequence where Bruce and Stark chit chat about Ultron (the first time), Bruce looks lame. Seems like they are tying too hard.
Black Widow - Pretty ok, but the lullaby shit looks ridiculous onscreen.
Hawkeye - Character is relatively better when compared to the earlier film, but his limited moves with the bow just seems too videogame-ish.