I have an Advantage Arms .22 conversion for my Glock 19, and several stand alone .22 pistols.
The AA kit is neither as reliable, or as accurate, as any of the .22 pistols.
What it is good for, is increased training with your carry gun. Trigger feel, target transitions, holster work, that kind of stuff.
For just shooting for fun, the .22 pistols are more, well, fun.