I would normally say go CZ. Indeed, I refuse personally to buy a 9mm Witness (or .40). However, I do own a .45 Witness and prefer it to the CZ-97. I also prefer the safety and firing pin block design with the Witness as the first is more universal and the second is sturdier. The chromed Wonder Finish is also pretty tough, if stupidly named (along with the pistol name, but I digress). Mine is the blackened finish (which I recently refinished with alumahyde) and has been a flawless performer. Yeah, truly a flawless performer, not a hitch, hiccup, or delay. It remains my favorite .45 pistol (I got into Witnesses before the CZ-97 showed up, a .45 CZ-75, what a country!).
With that in mind, a 9mm Witness in Wonderfinish makes a good run for the money against a CZ. Design-wise, I consider the Witness to be a better pistol. In application and construction, however, the CZ wins hands down. Also, the CZ will retain its value much better than the Witness.
Currently, I own a pre "B", a transitional, a "B", and a CZ-85 compact, in addition to my Witness.
Ash