IWB-Inside Waist Band: I am using a Comp-Tac for my Kahr PM9. I chose kydex because the holster stays open for easy re-holstering unlike other IWB soft leathers or suede holsters.
OWB-Outside Waist Band: I am using a Blackhawk Serpa for my Glock 27 & 22. I chose carbon composite because it locks into place upon re-holstering. There are no snap thumb breaks to get in the way. An index finger button is all it takes to release the pistol. Its one fast natural movement.
Carrying concealed requires a lot of compromises. I like the OWB holsters best. I find them the most comfortable and functional. But for those, it's a winter time deal, as with most summer attire, it's hard for me to keep concealed using that method. For summer I go with pocket carry with an appropriate sized gun.
Work days, (I own my business) I carry my gun into the office in a nylon carry case, and then it goes in my desk drawer. It would be difficult to wear it around working and dealing with customers. When I go out to see a customer or whatever, it goes into the car counsole. Not the best method, I know, but better than nothing.
I carry IWB as much as I can and have several holsters to do so with, and you are correct....each gun has a holster that is the best for that gun. Unfortunately it has cost me waaay to much to determine which is best for me and my guns.
Wilson Combat Professional in a Milt Sparks Versa Max 2
Springfield XD45 Service in a Brommeland Max Con V
Browning Hi Power in a Wilson Combat IWB Holster
Kel-Tec PF9 in a Galco Leather Pocket Holster....my go everywhere gun.
No matter the season, 99% of the time I'm carrying my HK P2000SK in a Milt Sparks VMII with a belt from TheBeltMan (a good belt makes a huge difference). I have found this to be the perfect carry setup for me. It doesn't matter if I'm wearing jeans and a jacket or shorts and t-shirt, this combo works great for me. I've got a VMII for my 1911 Commander as well.