Jesus [bleep] Christ.
You either wanna wear IWB or you don't.
If you do, leather or Kydex matters not. The vast majority of people carrying today are wearing Kydex. For good reason.
Be kind to obese people, for them IWB vs. OWB is not easy decision to make. Luckily Safariland makes a holster suitable for fat people. Google Safariland 18 IWB. This will not shift regardless of belt vs. loop fit and you will not have to wear your belt very tight to prevent gun holster shifting, this should help a lot for those with Michalin Man bodies.
