The MK9's are easy to carry appendix. I do it often. The shorter barrel keeps it from poking or jabbing, especially if you angle it. Anything beyond a 3" barrel is what I have trouble with, unless it is riding super high.
I've had great luck with the MK's we have. Really would like a K9 for OWB carry someday. I seem to like the metal frames more than the polymers, but everyone has their own preferences.
A PM45 would be (very) nice too.
If you get the CW9 I bet you'll like it.
http://i891.photobucket.com/albums/a...rMAG10/MK9.jpg