75b because it hosts the all steel Kadet conversion, the combination of which is a platform for a terrific bullseye competition pistol. Add a CGW 10x bushing to a 9mm 75B slide and you have a centerfire bullseye pistol, too.
But I can't choose between the polymer guns. I've shot the P-10F the most over the last two years, but the P-10S is the most surprisingly good at long distances, but I carry a P-07 and have two P-09 hammer guns because they work so well for everything centerfire that I'm interested in.
The 97B is a scaled up version of a 75B, and is my preference over any other .45 available, with a CGW "E" bushing. Period.
Choosing between them is futile. On this current trip, I brought the 75B Kadet, 97B"E", P-07, and P-10F/S pistols because I couldn't choose just two. And a few boxes of ammo for each. Good to have choices. So far, I've only shot the P-10F and S, however. At 100 yards, my one and only current specialty, and one where the striker polymer CZ guns excel, surprisingly.
Joe