I don't doubt that some guns allow the shooter to be faster and more accurate -- but that's arguably a very PERSONAL thing. What works for them might not work for you.
A related discussion showed up in another section on this forum, where they were discussing recent changes to IDPA Point Down penalties... several felt that increasing the penalties helped the slower shooter. Other disagreed.
In my experience, the best shooters seldom had that many points down, so from my point of view, it not a big deal.
I don't do USPSA (or know much about IPSC) but Bruce Gray, of Gray Guns, who was once a pretty good competitor -- and may still be, for all I know -- and who still tunes the guns of other pretty good competitors has said -- it may be on his website -- that he and others have found that being fast and accurate is important, but being fast ELSEWHERE (as you go through course of fire, moving from target to target, position to position) was where the biggest point advantage was to be found.
When you shoot production, perhaps this isn't as big an issue in the other divisions? As I said, I'm not familiar with USPSA or IPSC.
When I've watched some VERY GOOD shooters perform (and I can't think of a better term), they seem a bit like time and motion study experts who were also ballet-trained: no wasted motion, no inefficient behaviors. You don't hear folks talk about THAT aspect of competiion much here or by the folks who compete in USPSA or IDPA. (I haven't shot competitively in several years so I haven't had a chance to put it to the test.)