I've got both Glock with Advantage Arms .22 conversion kit and a Sig 226 with .22 upper. I had the Glock first then picked up the Sig. The Advantage Arms kit for Glock is good but needs high end ammo, CCI Mini mags or Rem Golden bullets. The Sig will run just about anything but really likes Rem Golden Bullets, (very difficult to find these days), and Rem Thunderbolts, (not so hard to find, but messier than RGBs). I prefer the Sig, it fits my hand better than the Glock, which is too bad because the Glock is a great pistol. It's really your call which pistol your prefer. I'll be selling my Glock and conversion kit in the near future to raise funds for a Sig p320.