While I have shot several Kimber .45's, I haven't purchased one. I do have a Colt M1991 but my preferred .45 is my H&K USP.
Depends on the ammo and distance. At 100+ yards, I have little problem hitting with 9mm, but .45 fails. Even at close range, my 9mm gold dot 147 grainers at about 1000 fps seem to peerform every bit as well as standard .45 loads in gelatin and have significantly more penetration.
I personaly do not like the double action curved triggers of HK and others, nor the toy gun like feel it gives. The straight back trigger of SA guns seem much more professional to me from a marksmanship point of view.