Okay, so this is the kit atop my 70s Era Gold Cup lower.

Kit was marketed by ATI. Cost $200 and came with two magazines.

First the cons. It likes Hi-speed ammo and not all ammos with the name "Hi-Speed" are high speed enough. CCI Mini-Mags performed flawlessly.

Winchester "Hi-Speed" ammo didn't. But it wasn't bad - and I'll touch on that.

Both ammos shot high, about 2" at 15 yards benched. Both turned in really nice groups, at 1.5 or less at that range for 10 shots per group, and I believe the fact that I need bifocals and was shooting without corrective lenses may have contributed to this, but I'd doubt the kit will shoot too much smaller than this.

The gun comes with two different front sights, so one can change them out quickly to change elevations.

The recoil spring is light! It gives the impression that it doesn't have the strength to chamber a round. It does have this strength. The problem comes with lower speed ammo. To overcome the slide weight and the hammer spring resistance, a hotter .22lr is needed for total reliability. But, it should be noted the WW High Speed ammo actually performed perfectly "AFTER" three rounds were fired from either magazine. It seems that the drag of the rims on the underside of the slide when under full magazine force, may offer just enough resistance to prevent the slide from going all the way back. This was evidenced by the failure to engage the sear. The hammer kept falling to half cock. It ejected the spent brass, but didn't pick up a fresh cartridge. After three rounds, the remaining rounds in both magazines fed and ejected appropriately.

The slide is aluminum with a steel insert for the breech face. I've seen photos of used GSG 1911 .22lr pistols where the slide stop notch is a bit battered. To prevent this, or at least slow it down, I counted rounds and when I got to 9, I dropped the mag before firing #10 so that the slide stop wouldn't engage. However, I did fire a couple mags just to see if the slide stop engaged appropriately, and it did.

My feeling is, this kit is a good buy, and I actually believe it makes more sense than buying a dedicated .22lr 1911 GSG. First, the dedicated gun has a more complicated takedown, whereas the kit takes down from the frame exactly like a 1911. It can be switched back and forth literally in less than a minute. One can put it on, take it off and be shooting either caliber in less time than it takes to simply remove the slide from the dedicated gun. And if you like your primary trigger, you never have to learn another trigger pull.

I think mine was a good buy.