Only time I notice problems with my conversion kit is when it's very dirty or the shooter isn't holding the pistol correctly. One biggie that's sure to cause a malfunction is "limp wristing". Other than that, the conversion kit works great. One catch is that you have to use the proper ammo. Advantage Arms provides a list of recommendations. I opt to use CCI Mini-Mags through my conversion kit. Not the most inexpesive .22LR cartridges, but surely a lot less expensive than .40 s&w or 9mm.
gf