I'm a moderator on the CZ Forum, and have participated there for years. I've had a BUNCH of CZs. I still have several -- along with two Sphinxs. I like them, but like other guns, too, so I'm not out to defend something out of some ill-place devotion to a brand.
We have 7000+ members on the CZ Forum, including many long-term owners. The number of broken slide stops mentioned/discussed there are in the "TENS", not "HUNDREDS" which makes me think its not a big deal. (Forums like that tend to attract the problem guns, as folks want to vent, etc.)
Several shooters on the forum have had multiple breaks in the same gun -- which has caused us to believe something in those guns were out of spec. In at least two of those cases, CZ replaced the gun.
As for 1400-1500 round slide-stop life: you're mixing apples and oranges...
CZ does NOT recommend replacing slide stops every 1400-1500 rounds on its standard guns like the 75B. The Tactical Sport, on the other hand, is a competition gun and they do a LOT of different things with it, including special mags, triggers, etc. Different gun, actually, based on the same general design, but bigger all over.
CZ mags aren't notorious for being undersprung -- but their other springs, like the extractor spring, were generally quickly replaced. Factory mags now are made by Mec-Gar and are good mags. The oldest CZ mags were as good as you get.
There was a period, about a year a go, when they had a run of bad springs -- trigger springs and mag springs, but again, complaints in the low number (probably under 100) on the CZ Forum. That seems to have been remedied.
Your claims, based on a glimmer of truth, are not representative of a much larger group's experience.
I've got a CZ-85 Combat with 10,000+ rounds through it and no slide stop breaks, no trigger spring breaks, and I replaced the extractor spring just out of concern -- although it had been shooting fine. I put a slightly heavier recoil spring in it -- a 16# version -- but later converted to a BHP 14# that fit the guide rod better than the Wolff Spring for the CZ (which is really made for the EAA Witness, which has a larger-diameter guide rod.)