Yeah, it's great. I'm using a Moto G3 from 2015 that continues to get weekly updates (although still on 17.1 at the moment) and I have no complaints. Only app with any issues is Firefox for Mobile - sometimes a single webpage will use up all the RAM and crash repeatedly - so I've changed to the stock browser.
Seconding the "turning _current_ devices into useful devices" sentiment too. My Samsung T720 (Tablet S5e) had 15-20GB main storage capacity with the stock ROM's partition scheme, but 50GB with LineageOS. Absolutely ridiculous. I'd never buy a tablet without LineageOS support.