Boston - really don't want Westbrook. Reasons being:
1. He doesn't play within a system. He wants to dominate the ball
2. He isn't a cerebral player, he’s an emotional player. Playing with emotion isn't a bad thing necessarily, bit it's a bad fit with Stevens
3. He shipwrecks your chemistry and playcalling at the end of games. Thunder were notorious last few years for losing games in the last 2 minutes because of Westbrook
4. He doesn't appear to be coachable. I always thought Scott Brooks was the cause of Thunder iso-ball, but Donovan couldn't break Westbrook's iso heavy tendencies.
5. I firmly believe Westbrook is a big reason Ibaka wanted out of OKC and Durant ultimately left
6. He will NOT age well. He is an iffy shooter at best and relies solely on a lightning quick first step and burst at the rim. Once he loses that, he loses his effectiveness. Athletic PGs do not age well. Ask Steve Francis
7. He is not elite defensively anymore. His defense fell of a cliff last year. Tons of James Harden-esque mental lapses and Rondo-esque laziness/ reaching / going for steals.