I kind of did this backwards. I bought an MK9 b/c my dealer was trying to move one he'd had. Liked it so much I bought the K9. Later the PM9. All have been very reliable with just about anything I put through them. I don't particularly care for the fact that I have to use a few light taps with a hammer (nylon head, btw) to remove the slide stop for field stripping, but otherwise everything had been great.