I also got mine NIR, and while it would run for 20-30 rounds, as soon as it got a little sooty, it would start to malfunction. Your list of fixes exactly matches mine: New/adjusted extractor, rew recoil springs, tweak mag follower for proper angle and engagement with slide stop, dimple slide stop to prevent premature lock-back, extra-power mag springs, taller rear sight to get POA/POI agreement. After the fiddling, the gun has run great. One minor bobble in the last 800 rounds. I've run the gun through two 90-round IDPA qualifiers without a problem. I take extra care in keeping the gun clean and lubricated, as I think the compromises necessary in shrinking the 1911 down to Combat Master size have removed a large measure of the 1911's inherent reliability and durability. When introduced, the CM cost about 50% more than a Commander, so there's no excuse for their not running right. My gun shows evidence of the hammer/sear having been hand fitted, so you'd think they could have paid some attention to the functioning, as well.