I've owned a PM9 in the past, and I just picked up an LC9. I haven't shot the LC9 yet, but as far as pocket carry goes, I find the LC9 prints less and is easier to draw from a pocket. This is due to the sloped design at the back of the slide vs. the square profile of the PM9. The LC9 is a tad bit bigger, but it holds 8 rounds instead of 7 for the PM9, and I can get a much better grip on the LC9. The mags seem to be high quality, unlike the Kahr mags that like to dump their rounds out if not handled gingerly. (My experience with the 9mm Kahrs, at least)
I don't particularly care for the "safety" features on the LC9, but they are unobtrusive, so I can live with them. The trigger is a long DA pull, reminds me of a PF9. The Kahr trigger is lighter and breaks earlier.
Range reports so far are very good for the LC9, so we'll see. If mine eats 200 rounds of mixed ammo in one session without a burp, it will be my new pocket rocket.
Not to knock you Kel Tec owners out there, I have a P-11 that runs great, but I think the Ruger LC9 is a better made gun overall. At least as far as looks go anyway. When I compair my LCP with my P-11, I think the Ruger has the edge overall. JMHO.
If money is an issue, I would take the cm9 for $417 from buds. More or less identical to the pm9 just cheaper.
If money does not matter I would love a solo 9. Feels great in my hand, its plenty small but a little heavy. However I think the stainless version is gorgeous!
The lc9 is nice and shoots well in my personal experience however its the largest of the 3.
I have shot all but the kimber but I own 2 kimbers currently and love them.