I've had numerous Rugers and CZ's-specifically, a Ruger P85, P89, P89TH, P90 Police Special, P94TH, SP101, GP100 3", GP100 4", Security Six, M77RSI, and a P97, for the Rugers; regarding CZ's, I've had 2 CZ75B's, a CZ83 .380 and a CZ83 9mm Makarov. In my opinion, handle and fire both guns if possible. Recent offerings from both manufacturers have been excellent, as is aftermarket support. Accuracy and fit and finish has been significantly improved on current P89's, and they also come with improved stainless steel magazines. The ergonomics of the P89 are not as bad in my opinion as others have alluded-I find the P89's safety/decocker significantly easier to use than the safety on the CZ75. Unless you have the CZ75 decocker version, lowering the hammer on a chambered round for a double-action first shot requires pulling the trigger. Although CZ has reshaped the trigger, it is still placed somewhat far foward for the first double action shot as well. Concealment is a wash regarding both guns-more dependant upon the holster chosen than the gun per se (as is the case with most guns, I've found). Although both are well-built of quality materials, I would rate the Ruger just a bit better for durability and reliability in my experience. There really isn't a bad choice to be made here-again, the key thing is choosing the gun that works the best for you.
Best, Jon