The firing pin block adds a degree of safety both when dropping the hammer on a loaded chamber and if the loaded gun is dropped and it hits just right.
The first concern is legitimate, but over-rated. If you don't have the appropriate dexterity to safely drop a cocked hammer on loaded chamber, you need to 1) unload the gun, or 2) cock the hammer and put the safety on.
You can unload the gun without dropping the hammer, by dropping the magazine and then racking the slide to clear the loaded chamber.
Others here have mentioned concern in IDPA or IPSC competition about dropping the hammer on a range, before the start of competition. In that context, the gun is pointed down range, and everything is done very slowly and judiciously. (Its a lot less dangerous than running with a loaded gun, etc., which is done with IPSC and sometimes IDPA.)
The firing pin block CAN affect the trigger pull somewhat, but a good gunsmith can work around it. CZ's gunsmith, Mike, does, we're told, one of the best CZ trigger jobs available; its pricey ($120) but apparently well worth it. He isn't intimidated by the firing pin block.
The second issue is probably even MORE over-rated. As best I can tell, the gun would have to be carried hammer down, and it would have to fall from a much greater height than holster height, and then would have to hit just right, either on the muzzle, or hammer.... I have NEVER heard of an accidental discharge from a CZ that fits these [similar] scenarios.
If you're still concerned, get a CZ-75B (or better yet, the single-action version of the gun). If the trigger is an issue, have CZ do a trigger job.
You've got bunches of options consistent with your levels of concern and pocketbook.
