I had a witness match elit a few years back for matchs shooting. That model was a single action and darn accuraite. I had 6 mags for it. I had to tune the feed lips on only 1 mag and all all factory mags. And in my mind any pistol shoote should be able to tune feed lips if needed. The witness is for me are a bit heavy but helps to keep the 40 settled down a bit. I don't think you would have an issue with them and they are a very worthy pistol.
Henningshootsguns site is a usa factory shooter and sell a bunch of competition stuff and upgrade accessories to from comp holster to reflex mounts. Brian Enos has a section on his forum for competive shooters mainly and I think a new witness forum was about to open when I had to quit running and shooting. I had shot about 4000 rounds and had NO problems. Guy I sold it too still uses it 1 1/2 years later.