IMHO, SFO is probably the best airport to arrive at immigration wise. LAX is a little bit worse, but that's more of a 50/50 on whether someone's having a good day or not.
Dear god. MIA sucks even as a US citizen. Avoid it if you possibly can. (I used to live in Anguilla so I'd fly that route a lot, and always did a hop via SJU or to anywhere but MIA.)
Holy God, is MIA ever a donkey circus. That is the single worst place I've ever been (there's a peek into my knapsack of white male privilege for you all). That place would sour the sweetest vintage.