Over the past 15 years, I've probably owned and regularly shot 10 CZs of various types, and a number of "clones." I've owned MORE CZs than that, but picked them up at good prices and sold them for profits. This included a number of pre-Bs, and some hi-gloss blued 85 Combats. Beautiful guns, those hi-gloss blued 85 Combats...
I've never really had problems with any of them.
The ONLY CZ I have at the moment is an 85 Combat, which I've had since 1998, or thereabouts. The first magazine or two I experienced premature slide lock and immediately took it to my gunsmith. He noticed some "nudge" marks on the tip of the slide stop, removed a bit of metal off the slide stop, and it's been 100% ever since -- with well over 10K rounds through it. It's satin nickel, and still looks like new. The only maintenance -- lighter recoil spring (using a BHP spring) and replacement mag springs.
I also have a custom AT-84s, which is based on an early Tanfoglio version of the CZ, and it's one of my favorite guns. The gunsmith -- I bought it used, and it was supposedly worked on by Jim Boland --made it wonderful. (I don't know for sure that Boland did the work, and he's now dead -- but some of the enhancements LOOK LIKE HIS WORK, on guns that I know he built. If not his work, it's a good copy, and wonderfully done.) I've had a number of Witnesses and several Sphinxes. I have not had any of the Israeli CZ-pattern guns, or a Magnum Research gun (except an ASAI ONE PRO in .45, which I sold, but now regret having sold.)
With the exception of a Witness Sport Long Slide (.45), which had a major barrel problem and which had a FAILED sight (one of their expensive super sights), and which was not under warranty, they've all been 100%.
I'm now exploring in a different direction, and have a number of Glocks and SIGs, and a tuned S&W M&P Pro (in 9mm) which is fast becoming a favorite.
I have shot, but never owned any H&K handguns -- but have owned various other guns, including 1911s. Every manufacturer has a problem gun, from time to time.
I find it unusual, however, to hear of multiple CZ problems from one rental site or training location -- as in the example cited. One reason for my disbelief is until very recently, CZs were still relatively rare and just not encountered that often. That said, I would suspect there were also problems with SIGs and Glocks at those sites, but they just aren't remembered by the instructor, because those guns aren't "new" and worthy of special attention. At the range where I shoot, they don't really have problems with ANY of their guns, and CZs are in the rental mix. They just clean them regularly and they all keep on ticking. The examples cited may be legitimate, but I would argue they aren't necessarily typical.