For me the worst was probably the one I started with: Mac OS 7.5.2 on a PowerMac 7500

That was 2 years before Steve Jobs got back at Apple. Good times

...Then the OS got better, slowly, but surely. The first OS X was barely useable but that was part of the transition.
As for High Sierra, I think it's fine but it should perform on the same level, at least, as its predecessor, which it doesn't. I think Sierra was the first one, *for me*, where there was no real improvement over the previous version. I could use El Capitan and be perfectly fine with it, I don't use anything in Sierra that makes it a requirement, it's mainly to stay somewhat current, or at least not too old! I couldn't care less about the
sharing with friends and family stupid stuff, I just want a solid, fast and reliable OS. In that regard, High Sierra, and Sierra to an extent, are a step backward compared to El Cap, obvioulsy they're much better than Yosemite but that's not particularly difficult
Hopefully, 10.14 will bring some real improvement(s) that will justify the upgrade. But as it is now, High Sierra is certainly not a
must-have.