Let me start off by saying that there are many great threads at the Glocktalk (GT) Kahr Club ( http://glocktalk.com/forumdisplay.php?s ... orumid=111
). There are folks there with much more triggertime with the PM9 than me. That said, I love the gun and currently carry one as my primary off-duty backup gun (BUG). That role used to be held by my Kel Tec P3AT. I now only carry the P3AT when I need "deeper" concealment. My primary off-duty carry gun is my P9 Covert which combines the shorter PM9 grip length to a P9 slide. I like combining the two guns because they share the same magazines and manual-of-arms (to include DAO triggers).
Now to answer your questions, befitting the fact that the Kahr PM9 is the smallest/lightest of the Kahr semi-automatic line, the gun lends itself to pocket carry with holsters made for it. My pocket holster for this gun is David Stillwell's Pocket Companion XL kydex pocket holster ( http://www.grandfatheroak.com/Stockdesigns.html
), shown here:
The PM9 rides well in this holster, but you do need a pocket that is a bit on the large side or made of heavier material to carry it well. Tight jeans or pants won't work without giving the impression that you have a tumor on the leg. Of course most people don't notice lumps outside of the "obvious" ones. I usually wear tucked out shirts, so if the holster sticks out, the shirt will drape over it with no problems.
One thing about pocket carrying this gun is that it does not draw as smoothly as my smaller P3AT or (according to LEO acquaintances of mine) a revolver drawn from the pocket.
The PM9 has had it's "growing pains" that are for the most part resolved IMHO. Many threads have appeared on GT questioning the reliablity of the PM9 (in fact questioning the entire Kahr polymer line). Many feel that the all steel Kahrs are more reliable than the polymer guns. Since I don't own an all steel Kahr, I can't compare it to my polymer guns. Kahr recommends their customers to fire 200 break-in rounds before depending on this gun for anything. There's a lot a truth behind that. My P9 Covert which has not suffered any malfunctions in nearly 700 rounds. My new P45 has suffered two malfunctions in nearly 400 rounds.
The two biggest issues that PM9 owners faced were barrel and recoil spring recalls.
The issue regarding the barrel was that some were installed on PM9s that were causing reliablity problems...those barrels with roughly finished feedramps. The serial number (S/N) ranges for those PM9s are VA0003 -- VA9999, VB0004 -- VB0999. My PM9 fell within the affected S/N range.
Kahr's recall wasn't "mandatory" per se...they wanted a person to fire the 200 break-in rounds to see how their gun functioned and then turn in only the barrel if the gun suffered a lot of malfunctions. According to Dottie from Kahr, they polish the feedramp and return it to the owner. Some people I think had their barrels replaced though. My gun had four or five malfunctions out of 600 rounds or so...I purchased it from GT user cal45 who polished the feedramp before selling the gun. After those five or six malfunctions, I haven't had a problem since and the gun has over 1000 rounds fired through it. I never sent the barrel to Kahr.
The recoil spring assembly is a two-piece (I believe) affair with an inner spring and an outer spring. There were problems with the assembly with some earlier guns...I'm not sure of the S/N range of the affected guns.
Magazines for the PM9/MK9/P9 Covert include the six round magazine that fits flush with the bottom and an extended seven round magazine with a plastic sleeve. Both are reliable. In my experience, 9mm magazines for the other Kahrs, such as the K9/P9/T9/TP9 (which extended below the bottom of the PM9's grip and do not have a plastic sleeve) are reliable as well. I've fired a bunch of rounds out of an eight round magazine with no problems. A word about the Kahr 9mm magazines though....they tend to strip the first round accidently in some magazine pouches or if carried loose in the pockets. There's a thread on GT about that. My magazines (the flush fitting six and extended seven round magazines) experience that problem. I have not noticed that problem with my eight round magazine. I typically carry two seven round magazines in a Safariland double magazine pouch. The top round has never stripped out of the magazine while carried in that pouch.
The trigger pull on the PM9 is very nice. It is long with a long reset, but not bad at all. It is very smooth as well. All-in-all, the trigger pull for this DAO gun is very nice making this gun very shootable (and accurate despite it's short sight plane) in conjunction with it's very nice blocky sights.
Shooting the PM9 can be a handful with +P ammo, but it is controllable. I normally carry my PM9 with standard pressure Speer 124 grain Gold Dot JHPs.
Regarding comparisions in firing the PM9 to the Steyr M9 and S9, the Steyr recoil less due to greater mass and weight of the Steyrs. The S9's recoil recovery is much better than the PM9; especially when firing +P or +P+ rounds....then there are those wonderful trap/triangle sights!
I can post photos tomorrow of both the S9 and PM9 together tomorrow if you wish.
Place side-by-side, it appears that the S9 isn't much bigger than the PM9.....but when you observe the thickness of the two gun...well, that's when it's obvious that the PM9 is smaller.
About ammunition....I've fired at least 150 Federal 147 grain Hydra Shok JHPs through my PM9 with (if recall) only one malfunction....during the break-in period. The aforementioned Speer Gold Dot JHPs, various types of FMJ and Winchester Ranger-T 124 grain +P rounds have been fired through my gun with no problems since the break-in period.
Anyhow....what else can I say about the gun? It's good! I'm glad I purchased one. Oh, that and Kahr's customer service is a joy to work with. Nearly everyone on the GT's Kahr Club knows of Dottie, who is a joy to interact with.
I hope this rather lengthy response helps.
Go to GT's Kahr Club and read the posts....they are very informative.