If the goal is "pick one for CCW", and one ONLY, it'd be the 65 which is where I went.
But that's not how I shop for CCW. I view a CCW battery as being three guns:
1) Front-pocket mousegun, which is either a 22mag minirevolver of some sort, or a small 32ACP. It's always present, but is hard to get to unless you smell trouble and stand around with your hands in your pockets, in which case it's the speed king because you're already on the grip.
2) "The Always Gun": this is the small yet combat potent (200ft/lbs energy minimum) piece that you'll generally have on you at all times, and is "first at bat" when the balloon goes up. For me, it's generally a snubby-pattern of some sort, probably 38 or 357 but a damned fine case can be made for the 32H&RMaggie (or 9mm 5-shot w/moons). It's for fighting at close range, it resists being grabbed, it can't go out of battery on muzzle contact. I recommend IWB carry.
The 731UL is a fine gun for this role.
Most people stop there, or do so most of the time.
3) "The Genuine Fighting Handgun": this will be the size/power range of a full-size 1911 or K/L/GP100 4" class wheelgun. It's accurate, good for longer range, and is the *backup* gun once you've gotten to cover and extended the range with the first-at-bat snubbie. If the GFH is present, no reloads for the snubby are carried or desired, the GFH is the "reload". I don't think I'd carry this at all times, only where needed based on the threat level. It does NOT replace the snubby's carry position, it goes somewhere else (shoulder rig, fanny pack) so that your reach and draw to the "always" is 100% the same every time.
In a GFH slidegun, I have a lot of respect for the CZ-75 general pattern and operating drill. I'd stick with a wheelgun personally of course
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These three positions and roles correspond to the Tanto, Wakizashi and Katana of the Bushido, for similar reasons: "hideout surprise", "close quarters indoor fighter", "full combat piece" in that order (10", 18", 26" blades).
The general technique of going to a snubby first followed by bigger stuff comes from the playbook of Jim Cirillo of the NYPD stakeout squad. He survived a number of hairy fights in this fashion.