@hifiman5 --- I had a rec-o-vac for several years. Whenever I'd take a record off the shelf I hadn't played in a while I'd run it through the thing. And yes, It improved the sound in every way. Less groove noise. Better imaging and more intelligible lyrics...in particular more understandable baritones. Better instrumental timbres, especially massed strings. Less spitty sibilants. It raised an ungodly noise when it was operating but so what?
The trouble is that the device was not quite as bulletproof as it could've been. I had to get it rebuilt twice. When It came time to rebuild it a third time there was nobody to go to for repair. I ended up donating it to the local Salvation Army. I hope somebody was able to make it work again.