I thought this list was pretty interesting. It’s a survey of the carry choices of 100 Rangemaster certified firearms instructors.
Most commonly, they carry (almost every day) a 9mm striker-fired semi-auto, with about 80 percent falling in the compact to full-sized arena (very few mouse guns or subcompacts). Almost all waist-carry (concealed) IWB on the strong side, appendix to the back of the hip, in a Kydex holster. All have a round in the chamber, with about half carrying a secondary piece for a New York reload.
Hmm. I agree with most, but I do like my leather sometimes…