Not worried about Sheed going to Boston. I don't think the Hawks missed out on a prize free agent either. If Sheed thinks Boston is the best place to win another ring, he chose wrong. The East has gotten so much better the last couple of years, and Boston is getting old, obviously.
If Sheed had wanted a shot at another ring, he should have looked hard at San Antonio. They were interested. Adding Jefferson made them contenders in the West again, not that they weren't already.