I think the thing that determines where Lebron ends up is what Chris Bosh does.
Now, hear me out on this one: I believe Bosh has the same opt-out clause that Lebron does. Suppose Bosh opts out for 2014. Yeah, he's hurt his max-salary possibilities a bit playing third banana to the Lebron-Wade show, but he's still a young talented big man who can pass some and operate outside of the paint, and we all know how many teams drool over that. Say Bosh opts out of his deal and signs somewhere else. Miami is still over the cap, so they can't really offer more than exceptions, can they? Who are they really going to get to come in for that? So now you've got Lebron, an aging Wade, a potentially retired Miller and Ray (if the latter doesn't switch teams again), Cole, and . . . I don't know what else exactly. In that scenario, why wouldn't he opt out again and go anywhere but the Heat?
My only issue with Lebron coming back to Cleveland if I'm the Cavs is that you've got a lot of young talent there, and either they're going to crash and burn (in which case they're of no use to Lebron) or they're going to be amazing (in which case you're using Bird rights to sign them and going as far over the cap as the Heat are now.) And it's not like Cleveland's got the cash flow of Miami or LA or New York, so what happens when Irving -- the guy who has proudly become the face of the Cavs -- is up for his well-deserved pay-day? And speaking of that, how is that going to play in the locker room if Lebron comes back? He sucks up all the air in the room; is Irving going to want to defer to him? And should he have to? Bottom line: is Lebron more of a headache than he's worth in Cleveland?