I have for some years. The conversion kits I have are Colt products - I have no experience with other brands though I am considering getting one of the Ciener kits for an Officers Model.
The kits I have are reasonably accurate - about 2 inches at 25 yards with their favorite ammo. This seems to be about as good as it gets without custom work - though I've noticed an ad for Marvel's 1911 .22 Conversion that claims 1.25 inches or better groups at 50 yards. That would really impress me, but I'm not going to spend $350 to try one out.
I like them (the Colt kits) because of the floating chamber which simulates (creates?) recoil and thus makes using .22s in place of more expensive .45s more resonable for practice. But even with the floating chambers you're still a long way from comparable recoil with standard hardball.
The Ciener kits, I believe, have aluminum slides, but no floating chamber. Their shop info implies that using a lighter slide gives a similar impression of recoil as would a floating chamber - but I would think it would also substantially alter the balance of the gun. The Ciener kits are also advertised for the Commander and Officers frames.
As far as I know the Colt kits are sized only for the full sized 1911 frame. I have used them on a Commander frame but about 1/2 an inch of recoil spring shows. I've never had this lead to problems of feed or function, but admit a full length guide rod would have made me feel better. Even so, for less than sanitary conditions it leaves a large entrance for debris.
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Jim Fox