Another CZ vote here between the two. Simply a better gun.
I've owned both. Carried a Beretta M9 (model 92FS) on multiple combat deployments, qualified expert with it, etc. I've owned a shot the heck out of various CZ models (P07, Shadow, P01, 75 full and compact in various configurations, 82, 97, etc.).
The Beretta feels big, feels heavy, has anemic factory magazine capacity for its size (you can and should get larger aftermarket capacity mags), the slide mounted safety is all wrong (backwards and mounted on the slide - some report problems accidentally decocking the weapon during emergency clearing drills). The sights are tiny too, and would need replacing. I have big hands and to its credit it is a good feeling gun and fits my hands well. I do like it. But there are just much better guns available, especially for the price point.
The CZs are simply better guns. Better design, better inherent accuracy, frame mounted safety/decocker, better trigger, and greater capacity and lighter.
Aside from a barrel bushing issue with my 97 (irrelevant to the P09), I cannot think of a negative of the CZ lines. I will say that the sights on my P07 used a cheap paint that rubbed off, but that's an easy aftermarket fix and if I were to carry it I'd just replace any pistols factory sights with nite sites anyway for under $100. No brainer there with any factory gun.
For carry, I'd look at the P07.
