I did have a MIM sear break on a S&W 952 once.
My year old Kimber Stainless Target II 9mm came with a steel MSH.
Super accurate gun at 50 yards, feeds all my handloads, SWC, XTP, TMJ, TC, etc...
Doing my best distance shooting in years. Even managed to ring the 8" plates at 100 yards a few times.
No broken parts so far, but I did replace the extractor and firing pin stop to help target loads eject better. I smoothed up some of the internals, but left the sear and hammer alone. Trigger is really sweet.
The Swartz safety parts in the slide and frame are gone.
I feel like I just can't miss with this thing.