I picked Celtics in 5. Miami is good, but they've not played the same level of opponent as the Celtics have so far in these playoffs, particularly on defense. Atlanta and Philly w/o Embiid (and then a hobbled Embiid) aren't capable of stopping anyone while Boston has one of the best defenses since the 2004 Pistons. It will be harder for Miami to score on Boston than it will for Boston to score on Miami.
Boston - for the first time these playoffs - has the best player in the series. They've felled Durant and Giannis, and Butler is not nearly as dynamic as either of them (and his shooting can disappear big time). Plus, Boston can get to a lineup of five two-way players easier than Miami can. Oh, and also, Miami fans suck. Cs lose one in Miami but win the rest on their way to the finals.