I have actually seen in person, a Kimber that had the same malady. A Kimber Custom II stainless, that is.
Since S&W machined parts for Kimber in the past...maybe there is a connection?
That said, I have a 2 year old Springfield Armory 1911 that has had tons of ammo run through it and I have not seen any parts breakage yet. Maybe SA has the MIM thingy down a little better than some others. I also know several people that own SA 1911s and have never had a MIM part break. The worst problem of the Sa 1911s I hear of are the improperly tensioned extractors and crappy factory mags. A quick call to Wilsons and 30 minutes of work and you've cured that for good, so I don't call that a true problem.
Still, unless you buy a 1500-2000 dollar pistol, theres a good chance you're going to get some MIM parts. Colt, Kimber, S&W, Springfield - they all use these parts today. Colt also has several plastic parts, like triggers and mainspring housings on pistols that run 700-800 dollars and more. Cheapo parts are in all ends of the spectrum.
The only way to totally aviod the MIM thingy is to buy an older 1911, like my Series 70 Combat Commander - no MIM there.
- Brickboy240