I had a very refined Glock 17, but sold it. I later got a more-refined Glock 34.... (traded it for a tuned S&W M&P Pro, for someone who wanted to get back into Glocks for USPSA); I bought a Glock 35 to replace it. Those are the only three Glocks I've owned, and all were light, accurate, and reliable. I've shot my fastest qualifying rounds in IDPA shooting a Glock 34. (It may just have been a good day, but I'm consistently faster out of the holster to the first shot with a Glock and than with a CZ.)
I have had a number of CZs. Still have an 85 Combat, a well-gunsmithed 75B SA, and two clones: a Sphinx Compact, and a highly customized AT-84s. (Those last two are very fine guns, and exceptionally accurate. But they both cost far more than a standard CZ or Glock.) I find the CZ-based guns more fun to shoot.
I've seen CZs break. Slide stops and springs were the most common affliction, and extractor issues. They're not common problems but they happen. For about 6-7 years, I was a senior moderator on the old CZ Forum, and there we also heard of a few frames that had cracked (Arguably due to misaligned holes in the frame -- a production problem, not a design issue.) Very rare - and CZ replaced the guns. If there were as many CZs in the world as Glocks, we might hear of a few MORE CZ problems.
There are a LOT of Glocks in the world; not nearly as many CZs.
I've seen Glocks break. Saw one with frame rails that got damaged, and I've had a couple of spring breaks, myself (mostly trigger return springs.)
Which would be more reliable, over the long run? Hard to day. Maybe (but only maybe) the Glock.
I've never had problems with a Glock mag; I've had a lot of problems with CZ-compatible mags, but seldom with CZ Factory mags. And Glock mags are cheap. Very cheap.
Which trigger is better? Once it's broken in, the CZ in single-action trigger mode can be pretty darned good. But not always. The older Pre-B CZs were great, and once broken in, the triggers were like glass with a crisp break. But CZ made changes over the years, and the newer B model triggers often leave a lot to be desired. (The "camming" hammer in single-action mode is one issue that offends many.) (Some say, "just shoot'em", but having to shoot 500+ rounds to get a decent trigger is expensive; I'd rather pay a gunsmith to do it, and enjoy my shooting from the start.) And, if you're shooting from hammer down (or half-cocked), the first and second trigger pulls will be slightly different. This is a problem with a lot of guns, and you'll see it in the placement of the first two rounds in pistol competitions.
The CZ is more naturally pointing, and for some rapid shots that may matter. But, I've found that if I just use the sights, I can shoot the Glock as accurately as the CZ. The CZ might be better for point-shooting.
The Glock trigger will always be the same. And, they're generally not THAT bad! And for a very low cost, you can get a Ghost (or similar) trigger bar that greatly improves the trigger.
The Glock is lighter, and if you're carrying (concealed or not), that can be a big factor.
I think I prefer the Glock factory sights to the CZ sights, but that's a matter of personal preference. There is a good variety of after-market sights for both.
I like them both. There's no reason to defame one to build up the other, yet that seems to be the common practice on these types of forums. There are positives and negatives for both, and it's really a matter of PERSONAL PREFERENCE as to whether those positives and negatives matter for you.