Love mine. A friend has a PM9, and we have shot them together. Triggers and controls are the same. You can't tell the difference at the range.
I think that the PM9 has a dovetailed front sight vs. a staked sight on the CM9, and polygonal vs. cut rifling. The external machining on the slide is a little different, and the slide stop is a different construction. The differences save you a little money. I think the CMP9 is a great value. Good Luck!