Ezra has always been my favorite rider (since I started watching SX/MX in 2001), so I'm hoping he gives the title one more shot, and goes out on a high note. In the latest issue of Racer X, he says that this (or maybe next year) will be his last best chance for the 250cc Supercross Championship, and considering how this year has gone so far... I think he should try to go out on a high note.
I never got to see Lusk battle Jeremy for the title, and have only witnessed him win a main once, but he has straight up beat Reed, Carmichael, Windham and the rest in his heats by coming from behind. And the battles between him and Reed last year in the heat races and at Phoenix was some of the best racing I've ever seen in the 250 class. His speed and guts, I've never questioned. Bad luck has always been Ezra's number one competitor.
I suggest that Ezra heals up and races the last couple rounds of this season, and skips the Outdoors (like Jeremy), to spend time with his wife and child. Then decide on whether or not to retire.