I'm an instructor and I use a CZ 75 for my instructor demo gun and also when I take classes as a student. That same gun is my home defense pistol.
But, I don't carry the CZ on a regular basis as I found the large, all steel, gun is just too heavy for every day carry for me. I have carried it a few times, and I'm sure I will again some time, but it's not my EDC.
I usually carry either a S&W Model 65 with a 3" barrel or a lately a Sig 239 9mm.
I'd use the S&W as my "demo gun," except the vast majority of the drills I need to demo are pistol drills, not revolver drills. When I do demo a revolver, I use that S&W.