I've had the Ciener and the Advantage Arms conversions. They like faster ammo--say over 1200 FPS. Mine liked Remington Golden bullets, and they function quite well. When you do something silly, like shoot Federal Thunderbolts? Not so much. You have the world's finest box fed single shot at that point.

You'll like 'em.

I was shopping for one of these and read lots of forums and reviews. I came to the conclusion that the Advantage Arms was the one I wanted. It seemed to perform the best and was reasonably priced (comparatively speaking). Do some web searches and research.

Unfortunately, my Glock is a Gen4 and apparently there are no conversion kits on the market right now that will work with the Gen4s. If you have a pre-Gen4 model, then give Advantage Arms a look. If you have a Gen4, be patient or look for a .22 pistol.

I bought a Sig Mosquito -- it's about the same size, weight, and feel of a compact Glock (Glock 19 for example). The Mosquito was only about $75 more than the conversion kit.