Hello. I own and shoot both. Though I recently purchased a CZ75B 9mm, I sold it; my preference remains for the Pre-B pistols. I own 4 of those, which were purchased decades ago. Three of them are regularly used. Other than recoil springs, all are still on their original parts. I like the option of either carrying hammer down for a DA first-shot or cocked-and-locked as per my Hi Powers or 1911 pattern pistols.
I also own and shoot Glocks quite a lot. I have seen minor parts breakage in these during my years as a police firearm instructor (usually trigger-return springs), but saw a LOT more Glocks on various firing lines than than CZ's. I have seen one NIB Glock 19 slide that developed a circular crack on the breech face on its first outting using factory standard-pressure ammunition. Having said that, I regularly still see some first generation Glock 17's being shot by their owners even today! Other than recoil springs, and one striker spring, they're on their original parts.
This is the only major failure I've observed with any Glock pistol during 11 years as police firearm instructor. I did not take the picture, but I know the police photographer who did and the owner of the pistol worked under my command. Glock replaced the slide as soon as they were made aware of it. My Glocks continue to work just fine as have the vast majority of them I've observed.
For me, the CZ's are more comfortable, and while admittedly subjective, quite a few other shooters apparently feel the same way.
Internally, the CZ is more complex than the Glock. This is important to some, no so much to others, and some might not care at all. I prefer the Glock in this respect to the CZ, but admit to never "having" to detail-strip either. I did with the Glock simply because I so easily
could. "Important to me" does not necessarily translate to "Important to you"; each of us individually can probably best make that decision.
I am not sure if the CZ or Glock is more mechanically accurate, but find the former easier to shoot precisely. I attribute this to a couple of things; the CZ is heavier and easier (for me) to hold steady while applying trigger-pressure. It also has a lighter single-action trigger-pull than my Glocks do. That said, I have certainly seen some very nice shooting done with the Glock 17 (and other Glock models) as well.
If I could only have one of the two, it would be because I legally no longer had an option to own more. For that reason, I'd probably opt for the Glock simply because I have an ample supply of spare parts and the things are easy to detail-strip for parts replacement. On the other hand, were conditions such that I could only (legally) have either the G17 or the CZ75, I probably wouldn't be shooting or using the latter as heavily as in years past. (Make no mistake, I emphatically am not suggesting that the CZ75 is "fragile". It's been my observation that so long as recoil springs are alright, the things shoot and shoot and shoot and shoot;...you get the idea.
Again, a subjective viewpoint to be sure, but just as I find the CZ more comfortable than the Glock, I also find its lines "interesting" (for lack of a better term) and "elegant" in a dangerous sort of way...just like my favorite, the FN/Browning Hi Power.
If interested, more observations are here:
http://www.hipowersandhandguns.com/CZ75.htm
http://www.hipowersandhandguns.com/Critical Look at the Glock 17.htm
Best.