Mainly ambidextrous safety/decocker and slide release.
Also, the combat version has a different trigger that has adjustable reset.
Other than that it is the same as a 75B.
You can get the non-B version without the firing pin block...a bit nicer trigger.
If you are a lefty, get the 85.
Or if you want the combat trigger, the the 85B combat.
I recommend the Cz custom shop (Ghost products)
There is no more accurate 9mm that I have found.
Avoid Wolf Ammo and similar steel cased, matte finished ammo and Aguila.
It will shoot anything else.
If you want a tac rail, get the SP-01.
You will not regret a Cz purchase...better than Sig IMHO.