I bought a 10mm Witness not that long back. I had some issues at first with the magazine and the rounds not loading properly. I bought a new 15rd magazine and, after that, I have never had anything but perfect shooting. This is my favorite pistol right now. Since I got the new magazine, it has been as reliable as my Glock 23 and more reliable than my Springfield 1911.
The 10mm cartridge is awesome, but can be pricy buying ammo. A friend of mine just bought reloading supplies, and we have been playing with custom rounds now. THIS is fun.