My pocket holster is a Galco rough out that I have carried my Smith 642 in for 20 years. Not really any wear and tear other than a few slick spots in the rough out. Works well for me.
I have been using a PCS (Pocket Concealment System) pocket holster for my 340 PD for about 5 years. It's thin, doesn't collapse, stays upright in my pocket and it is just loose enough to stay in the pocket on the draw- (important!). I got it through Lightning Arms Sports. They have a good in stock selection and very fast service/shipping.
I see I'm in the minority here, but I use a Sticky holster. I got one when I bought my P365, and while that's a bit too heavy for me to pocket, I was impressed enough with it to buy one for J-frames. They're pretty reasonable.
I've come around to pocket carry the last few years... unfortunately, I'm slowly finding out that neither a "J" nor my SIG is enough to survive on the streets, so going forward I'm not going to waste the time arming myself.
I've used a Galco horsehide for my 642 for about 5 years. I am very pleased with it. Galco also makes one in a lighter weight suede leather. I had one and gave it away. The horsehide holds its shape, stays in the pocket when drawing and since the inside leather is smooth, so is the draw. I've used the Nemesis and Remora for autos, but I can't improve on the Galco for a J frame. I'm no Ninja, but I'm still here.
I have nothing but good things to say about the several Ken Null pocket holsters I own and use daily, including one for my 340PD J-Frame. I believe it is called the Pocket Scabbard. Has an ingenious "wing" that catches on the top of your pocket as you draw, leaving the gun in your hand while the holster remains in your pocket.
Great man to do business with. One of the few custom leatherworkers who answers the phone and talks to you when you call.
As mentioned above, this guy makes elegant thin leather pocket holsters. I have a couple or them and have been much impressed by their utility and construction.
I also never understood the attraction of those padded nylon pocket holsters that made you look like you were shoplifting a club sandwich.
Not a lot of experience with other pocket carry holsters but have both nemesis and mika for a 642 and am quite pleased. The mika seems to hold open better for re-holstering if that might be an issue.