I've had leather, nylon fabric, and Kydex...
Kydex is my favorite because of 1) the low-profile 2) solid feel and 3) quick release
I've had a CrossBreed horsehide & kydex for my Kimber 1911 for 30 days. It's comfortable, very concealable (IWB), well designed and tough as nails...kinda ugly though. Adapts well to the slight ponch around my waist. Outstanding combination of Kydex and leather.