I always was a lifetime "if it ain't made of leather, I don't want it" holster, sling, belt guy. Still am pretty much, but around five years ago I became familiar with a synthetic line of holsters that I now have three of for carrying concealed, all IWB. I became knowledgeable of them at a large gun show in my state from a dealer that carried them. Major, it's from right down in your state- Naples, Florida, called Remora. Website Remora.com. I carry concealed with no problem a Smith 60 38 Spec and Shield 9mm. Also no problem with a Colt Double Eagle Officers Model 45 acp 3 1/2". All carried IWB Appendix style with no problem, can be positioned side or back IWB, but prefer Appendix. Wearing a sweater, shirt untucked, no sight. I don't care for back position-to uncomfortable, side to noticeable, might as well be carrying OWB.
The Remora holsters are top quality and are made of a material that keeps them in place when moving about, sitting, etc. The holster stays in place when drawing, but being soft takes a little more to holster. I've compared them with another holster of the same type 'Sticky Holsters' and the Remora IMO is better quality and I'm finicky about construction and quality of a product. I wish they had been around back in the 70-90's era when I wore a badge. I carried my Smith Model 60 as a backup concealed on duty. Carried it right front, behind my 12 loop 357 Mag cartridge carrier in a Bucheimer suede leather clip on IWB holster (still have). The 60 never worked loose, even when 'tussling' with drunks and other arrests where physical combat took place. Carried it off duty at times also in the Bucheimer. Kydex, don't care for them inside. outside, or wherever. Too stiff and impersonal IMO. Might as well heat up a plastic pipe, flatten it, and strap it on. If your interested in something like the Remora's, check out their website. I've talked with them over the phone, very friendly outfit, give them and their product five stars.