This was in production when I was there.
It worked well in reality but died a bit when some of the non-fact marketing bollox stared swirling round the business so it "wasn't rigid enough" (it was from a record playing perspective)
I use a restored Z-100 in a secondary system. That old Syncho-Labe motor unit appears to be foolproof. It's difficult to obtain idler wheels, but the originals last a long time. You have to clean up all the hardened grease, but once that's done there's no parts that go bad. It's all metal (steel with some brass, and a few plastic trim pieces). Nothing like it would ever be made today.
If the Zero had a 'problem' it was that it came out (early 1970s) when cartridge makers (and the mainstream press) were all gaga over low tracking forces. The general idea was that if you were tracking a cartridge over 1 gram you were ruining your records. The American cartridge company, Empire, advertised that their cartridges could track at a tenth of a gram with a suitable arm (i.e., one that was never made). It was a ridiculous claim, but that's how it was back then. Another company, ADC, sold high compliance cartridges with such jiggly cantilever suspensions that buyers complained about high failure rates as the stylus would literally sink into the body, collapsed. Those sorts of high compliance low tracking force cartridges were not suited for use in the Garrard pantograph tonearm.
From experience I found that the Zero 100 arm does better with a bit more downward force than was thought 'safe' in those day. 1.5 to 1.75 grams with a 'modern' cartridge works well. Even 2.0g (which the latest Audio Technicas support) works fine. The best I've found are the Shure cartridges with the damping brush (which wasn't even invented at the time of the Z-100 and in any case are no longer made). Those control the arm satisfactorily and are an excellent match.
My take on late Garrard is that by the mid-70s they were answering a question few mainstream consumers were asking. For various reasons, audiofools at that time (like me) mostly gravitated to Japanese product which was generally superior in mechanical and electrical function, and more pleasing in cosmetic form. Compare the Technics SL-1350 fully auto turntable with any period Garrard (or Dual or Miracord etc.). Technics arm motion was smooth and linear, whereas European sourced automatics tended to be herky-jerky in their mechanical operation. Too, Japanese servo direct drive motors were much more exact than the rim drives, at least in smooth and silent operation. With a servo motor, speed was pretty much 'set it and forget it'. Mechanical rim drive required speed adjustment each time you started the record, because the idler would not contact the rim at the exact place. And with a stack of records speed was typically not as precise as with servo direct drive, due to the varying weight of the stack on the platter. Once quartz PLL came along it was all over for mid-range mechanical turntables.
Second, although most top end Garrards (Z-100, SL-95) were probably used as manual tables, a lot of people still thought of them as essentially multiple play automatics, and consumers were gravitating away from multiple play turntables by the mid '70s. I read somewhere that Garrard was sold to a Brazilian company; whatever happened to them they seemed to just fade away. That is my recollection. Dual? For their part, I read somewhere that United Audio employees (US importers of Dual) came to work one day and the doors were locked. No advance notice. Just no work. The company was history.
All that said, I understand Dual is back in business making record players for the Euro market, but I haven't seen them here in the States. I also use a Dual 704 which is going strong--originally made in 1977. On the 'high-end' Garrard 301/401s are through the roof. So what goes around...