I love my MK40. It's quite a bit heavier than the PM/CM series, which is fine in the winter but might tend to be uncomfortable in shorts. Therefore, I recently purchased a CM9 for summer carry. Both are the same size and carry well in the same pocket holster (I use a Desantis Nemesis). Both are extremely reliable, and reasonably accurate at 7 yards given my lack of formal training and infrequent trips to the range.
The recoil on the MK40 is noticeably sharper than on the CM9/PM9. Yesterday I fired 100 rounds through my CM9 and was only shaking a little toward the end. With the MK40, I'm done after 40-50 rounds. This is in spite of the MK40's felt recoil being diminished by its greater weight, so I can only imagine what the recoil would be like on a CM40/PM40. This is why I went with 9mm when I wanted a lightweight version.
The trigger pull on all three Kahrs I've owned (PM9, MK40, CM40) is smooth, and just long enough for me to feel comfortable with pocket carry. I wouldn't want to pocket carry a weapon with a short trigger and no manual safety.
