I have had My K100 for almost a year now....have shot some IPSC matches with it....the ergonomics of this pistol are amazing, especially for anyone with large hands, it is without a doubt the most comfortable and secure feeling gun I have ever shot. I had an extractor fail at about 1000 rounds, which Marstar replaced with no hassles. I have stripped and polished every moving part in the gun and it is very smooth now with DA at 9lbs and SA at 5lbs. The only complaint I have is that the gun has a very bad habit of "stovepiping", and the ejection of the spent cartridge is very inconsistent. ie, they never go the same place twice. Not a problem if shooting higher power loads like IVI, but for reloads for IPSC power factor, guaranteed stovepipe every 10-15 rounds...perhaps I need to change the recoil spring?.......had some problems with mags dropping out when new, but polished up the mechanism and groung the lug on the retainer to be more positive...never dropped another.