I have a Kimber conversion. Works great on my SA GI Stainless (actually, better than the "real" slide ...), and on my Defender. On the Defender the whole thing feels like it weights about as much as a Kel-Tec.
I like it for a bunch of reasons. Obviously, it has the same "hand feel" as whatever frame you're using. It's cheap to shoot. It fits nicely in a case with my Mk III and a 1911-du-jour. It means never having to run out of some sort of ammo. (Same reasoning as a 9mm Bar-Sto barrel for a .40 Sig., among others.)
I'm not crazy about the sights, but my eyes aren't as good with bullseye sights as they used to be.
Mine shoots Standard Velocity very well, once it's "warmed up." Forget Subsonic. (High Velocity preferred.)