It's not guaranteed to look bad. It would help even in your middle example where you clamp to one axis. I really think you need to play with it some more. You and I both know you can't get rid of distortion but you can minimize it to acceptable levels. Here is an example taken from the projection painter demo which…
Oh also, there is a newer option in 3dsmax 2012 called "Straighten Selection" which can be helpful also, it helps square off UV's again. Like EQ said the distortion on pieces is going to depend on difference in the shape and the way you unwrap it depends greatly on the material that is going to be applied. I'm not sure…
Relevant example: A: Virtually distortion free, will bake better/more friendly with smoothing groups(which means more compatible with various engines, compresses better, easier to generate detail map from etc), will look better if texture has any surface detail or pattern, slightly more annoying to paint on. B: Easier to…
Mark: You missed the point of what I was saying, of course on a completely unrelated example(minor distortion on an organic object with even texal density) a little distortion is going to be just fine. Baking from a high is excellent in that it covers for minor distortion, I never suggested otherwise. However; if you're…
It works with non-organic hard surface models that have minor to moderate distortion also. That's probably going to happen with it clamped in one direction also... But I agree, I'm not sure either approach would work best, probably the "wrong" example from the OP is best, but that depends on a few things that aren't said…