They are the darlings of the internet. I had a couple back in the 1990's when they were dirt cheap compared to most other guns. It was primarily the price that I found attractive, but after a few years I got out of the CZ game. The triggers were heavy and gritty, but despite that they did shoot very well.
For a time CZ sold some guns with poorly made springs, and mine were made during that time. After replacing all the gun and magazine springs they weren't that cheap anymore. Granted that issue has been corrected, but it left a bad taste in my mouth.
Both of mine had beavertails that curved DOWN and during recoil would dig into the web of my hand between the thumb and trigger finger. SOME current CZ's have corrected this, some still have the same design. That problem can be worked around if you choose the right model.
The deciding factor for me is the slide inside the frame and tiny ejection port. I couldn't see where it had any advantages, but a couple of disadvantages. Operating the slide was much more difficult than other guns with the more traditional slide outside the frame.
At the end of the day they are a just another decent option out of lots of other decent options if the design works for you. I think most people like them just because they are different. For a long time, they were highly sought after simply because they were unobtainable. Not necessarily because they were better. The basic design is about 50 years old, designed at the same time as the Beretta 92. I think for serious work there are better options.