Marvin Williams at times last year was great. I can vividly recall the game when he dropped 30 on the Wizards (not a huge accomplishment), but it's something.
But I also vividly recall when he was cold, and constantly injured at the end of the season.
The Hawks have Mo Evans who had a great record when he started and is by far a better defender.
Atlanta should go out and make a bid for one of Boston's two big boys or maybe a Big Baby? Leon Powe and Glenn Davis would be a great addition to the team; they would give another low-post presence with Al Horford and Pachulia and could become the starter at power forward.
While it is unlikely to get "Big Baby" because he is a restricted free agent and Boston seems to have every intention of matching any offer, I think Powe could be lured in. It would be an upgrade over Marvin.
I say let him walk.