Yes, I am using the plain vanilla, ancient, original MC that produces topological inconsistencies (writing that makes it seem worse than it is, because, really, the cracks generally seem to be just that; cracks, not gaping holes; each boundary consists of an even number of edges where the majority of the angle is distributed amongst all but two of the vertices) -- I've once tried the version with topological guarantees / case ambiguity resolution by Lewiner, et al. back in the mid-200x's, but I went with the version from Bourke's site in the end because it does a relatively decent job with relatively minimal headache.
I updated the first post to indicate that I'm using the standard, original MC algorithm (see: P. Bourke's 'Polygonising a scalar field').
If anyone has a full, cost-free, public domain C++ implementation of an adaptive MC algorithm to share, I'd be more than happy to absorb it into my toolkit -- perhaps GD could consider the possibility of adding in a 'recipes' section of the site to gather all of these kinds of things into one nicely organized spot. Apparently I implemented one when I was experimenting back in the mid-200x's and I forgot.
In any case, the major point of the post was mesh smoothing -- if anyone has any kind of implementation of Taubin smoothing that uses 'Fujiwara' (scale-dependent) or curvature normal (cotan) weighting, but doesn't destroy the mesh, that would be nice too. I've had no luck with these; the literature is abundant (to the point where it's conflicting).