Wet Dog,
I have a kimber conversion and shoot it pretty often with a springfield armory grip frame. The slide is aluminum, don't know if that makes a difference to you. It of course makes the gun run differently, slide being real light and all. I don't mind on a fun/hunting pistol.
I've ran several thousand rounds through it. Never had a single malfunction with jacketed ammo. After a couple hundred rounds of hard cast lead bullets, it will gob up. Not that big a deal, just a pain to clean out. I hear this is normal for any .22 conversion kit. Accuracy is top notch. Wouldn't trade mine. Hope that helps.