A straight shoulder is one for me, too. Trying to get any kind or reach or smoothness is near to impossible. (Though a straight shoulder should theoretically eventually lead to soundness issues on a horse that is used). Your argument against the high-set neck is convincing. I don't think I've seen a neck that is that high. I've been noticing a lot of low set necks, or as Fugly would say "nests". One of the yearlings I worked with this last year had a higher set neck than the others. It gave her more of an Arabian look, rather than reining bred Quarter horse. It didn't help that she had a delicate head. lol But, she had a huge, powerfully built body, and rear end. I'm assuming that since she moved nicely, naturally, that her neck was not as high set as you are talking about, though.