As already mentioned, the factory mag is not the best. Burrs on the inside of the stamping at the top edges (inside) cause extra friction, sometimes preventing proper feeding. I used a diamond-dust sharpening stone to knock off the burrs, and I've NEVER had a failure to feed since...
Accuracy is phenomenal right out of the box, and the trigger is incredibly smooth. If you're an "ok" shooter, this will make you a "very good" shooter. When I got good with this (SS-II, .45, box-stock), I went back to my "cheap" pistols, and was a much better shot... trigger control, recoil, flinching issues, all gone. You won't be disappointed!
Los Angeles, CA