>> The condensation you are talking about does not have the purifying effect of boiling.
Of course it does. What difference does it make where the water vapor comes from? (Other than crud it picks up off of the wall of the condenser, of course, but that is a problem in a still, too.) The water from a still isn't "clean" because it was boiled. It is "clean" because water vapor doesn't carry crud and bugs any more than oxygen does. It's a gas.
Distillation does not really require boiling in the way that you mean it. It just needs vapor. For instance, a solar still produces essentially pure water, and nothing gets boiled in a solar still. (Well, there ARE pretty intense commercial solar stills nowadays. I am instead referring to the old "clear plastic over a hole in the ground" kind of solar still.)
I suppose you could make a stretch and say that a lot of the condensate comes from microdroplets rather than vapor, but the microdroplets invariably are formed from water vapor as well. So, I don't think it matters.
>> why not try and perfect using a vapor barrier sleeping system.
I think that's a pretty profound point. It does, however, make the assumption that we're talking about condensing one's own perspiration, rather than condensing ambient moisture. I guess that condensing ambient moisture would be heavily dependent upon weather and other conditions, though. Probably not something to depend upon.