Not sure he's as thrilled with his time in Miami as some of these comments are making it seem. Dwayne Wade has never exactly publicly backed him and as great as he's been that team hasn't exactly been lighting the world on fire. He sees the Miami media questioning his value, and the fans weren't exactly campaigning for him to get into the All Star game.
A lot of the reasons many of us are bullish on Whiteside are the same reason Heat fans and possibly their front office are. He slows down your offense, he isn't the best practice player(which probably bothers a gym rat like Wade more than he'd publicly admit) and he doesn't really have that clean cut, alpha dog, Max contract kind of mentality despite the fact that he's produced enough to earn one.
What makes me think he'd fit in Boston, is that A. Whiteside is the most available max contract guy in a long time and B. it's possible that he'd do better in a grittier more blue collar Boston style environment than the high society classy Miami atmosphere.
All of that being said I'm sticking to my prediction that he'll be a Maverick next year. After missing out on Deandre and Dwight playing in rival Houston I just feel like that team is fiending for a franchise center and Cuban would love to stick it to the Heat by taking their theirs. Could see Cuban's offer blowing everyone else out of the water.