I'm an active member on the Walther forum, and I've owned, shot, and carried 99-series pistols since the early-mid 2000's. As far as CZ pistols, I've owned an 85B and a 75B SA, and just recently got a P01 Omega.
As was stated earlier, they are both pretty different. I think your preference in trigger action will decide with is "better" for whatever role you will be using it for. Both pistols are considered by many to be one of the easiest to shoot accurately compared to other comparable pistols in the same category.