I switched to YouTube TV from Sling several months ago. Sling was OK, but I was paying for way more channels that we would ever watch - YouTube is cheaper and still has the channels we actually do watch.
That said, I am seeing a few glitches - not entirely sure whether to blame YouTube or ROKU, but I suspect ROKU is the problem. Basically, we occasionally lose sound or lock up upon turning it on. Cycling power to the ROKU gets everything working again. But this rarely happened with Sling.
I am not a fan of the user interface for YouTube TV - not as intuitive as Sling or a typical cable box. YouTube TV will not pause anything beyond about 20 minutes, so if you don't come back in that time, you lost your place and can't go back - I find that extremely annoying. Recordings work fine, but again, not as easy as Sling. But for the lower cost, I've been OK with these issues.