My 2 cents :
Boston trades: 16th pick, Jason Terry
Spurs trade: Danny Green, Tiago Splitter, 28th pick
Why for Boston: I'm not a fan of drafting yet another project player. I'd like to try to make one last run while (or if) KG and Pierce are still in the building. I think that with them will be our closest chance to a championship in a while.
Terry has...well...not exactly been amazing. He has the vet swagger, though. That might be his best attribute so far overall - his defense sometimes was impressing, and his 3 point 2nd quarter barrage in game 2 was also fun to watch, but at the end of the day, he's an old guy that's only 6'2.
Why for Spurs: The Spurs are one of, if not, the best drafting team in the league. They are amazing - they are constantly able to find gems in the draft. They had a mid round pick a couple years ago, and it turned into rising star Kawhi Leonard. I think they'd love to get their hands on the 16th pick. Terry is also a very good role player still. Popovich can find a way to implement the vet into his system. I think Terry would fit better with the Spurs rather than the Celtics.