Honestly, I think this lens has an undeservedly bad reputation among "technical" reviewers on the internet. I'm sure it sucks at shooting test charts wide open. I don't shoot test charts - I shoot people indoors (groups, activity-based portraits, etc) with this lens on an original 5D with wide...
Small; great build; very sharp away from extreme corners
slightly soft wide open - clears up by f/2.2; hood not included