MW is obviously much better in this regard than theism, but one of the problems with theism (it promises a simple reduction, but leaves the 'simple' undemonstrated) is interestingly analogous to the problem with MW (it promises a simple reduction, but leaves the 'reduction' undemonstrated). I don't take this to be a distinct argument against MW; I just wanted to call it to attention.

I guess we'll have to wait until we have interstellar travels to observe completely superposed civilisations so that we can actually see MW? That was a joke, by the way.

If your commitment to locality is strong enough, then you can recover locality by positing that you've imperceptibly fallen into another world in interacting with one of the particles, dragging everything around you into a somehow-distinct component of a larger, quasi-dialetheist (really, complex) reality. I don't begrudge those who pursue this path; I only encourage careful scrutiny of exactly which priors we're appealing to in taking that first step away from the naive, superficial interpretation of the experimental result that caused this aspect of the problem.

It's not really "fallen into another world" as much as "being in a superposed state." If you assume that superposition is a real effect of wavefunctions (particles), then you have to assume that you also belong in states. The only way of escaping that is not believing superposition is an actual, real effect, which to me looks like exactly what Bohm says. Now I'm not saying that I give a > .9 probability to MW. It's > .5, but I do not trust my own ability to gauge my probability estimates the way you did.

I don't find the idea of clearly distinct universes mystical or strange or scary. I do find it strange and very-nearly-incoherent to think of worlds 'bleeding together' at the edges; and I very much wonder what it would be like to fully inhabit that intersection between worlds.

Point. I think mr. Yudkowsky mentioned something about a non-existence of worlds at that intersection? As in, the leakage from the "larger" worlds is so big that the intersection ceases existing, and then you have clearly distinct universes. Or at least that's what I understood. I don't think I like or even agree with the idea; it, too, sounds to me like trying to fit physics into intuition. But anyway, I agree with you that one of the main points in my head against MW is that intersection. That, and what I mentioned above, of completely impossible situations (like zombie Kennedy) never having happened in recorded history.

BM requires some really unpleasant initial commitments, but there don't seem to be any special interpretive problems, paradoxes, or unsolved problems in BM, aside from the 'ordinary' legwork required in any general microphysical theory (e.g., we need a Bohmian QFT). BM has solved the Measurement Problem; MW merely has some really suggestive hints that it might someday offer a more elegant solution of its own.

Point. Which is why I agree with you that BM is the only other serious candidate. [whine]But those initial commitments are really unpleasant.[/whine]

The sole difficulty BM faces, in contrast, is that it's just kind of... ugly. Overtly, avowedly, unabashedly ugly. (That's really what I respect most about the theory. It doesn't hide its flaws; it defines itself in terms of them.) But until these same problems have been solved in at least one of BM's competitors, we have no way of knowing that some analogous ugliness (like 'magical reality fluid') won't be demanded in the end in any empirically adequate interpretation! Scary thought, eh?

Scary indeed. Magical reality fluid actually terrifies me, and if it turns out that MW requires it... well, I think I prefer non-locality to that.