you can always hit BG on the head with it if you have a jam
I absolutely LOVE my P40, although the trigger pin did walk. But Kahr sent FedEx to pick it up for free, fixed it, and sent it back inside of 2 weeks. I'll be range testing it tomorrow. I've already got my order in for the PM9, due next month.
The P40 does have more recoil than any other pistol I currently own, but it's not terrible. More than an Ultralight .38 firing +P's, less than a Snubby .357 magnum. It's on par with or slightly more than a Glock 27.
As for how they compare to the steel ones, my personal experience is this. Of course they do recoil more than steel because of the weight. But I could tell a big difference when toting my wife's MK9 during the .40's 2 week hiatus. I wore the wrong belt to the mall, and it made my hips sore from pulling on them. I was constantly wiggling and adjusting... I just knew security would be out any minute. I have worn that belt with the P40 and it didn't have that effect. I really can't feel the 40 back there at all, although I'm aware that it is.
Don't get me wrong, the Steel ones are 100% stone reliable, and I have confidently placed my wife's well being in the MK9's capable hands, but they are still HEAVY.
FWIW, I sold my MK40 to purchase p9 which eventually became a P40 (long story, early P9 with lots of problems), I have not regretted the decision since Kahr swapped me for the P40.
(Before that time, I gotta admit I was sorry I had done it.)
The new Polymer Kahr's appear to be "bug free".
Good luck on your decision!