YouTube TV just added PBS and keeps adding more channels all the time (no HBO yet but you can get it with Amazon Prime as an add-on or HBO Direct). I love YouTube TV for its super ease of use and access from anydevice and unlimited cloud DVR. I have been using it from when it first appeared and have had very few issues ever, even when I had only 3-5 Mbs internet service at times and still got HD-quality at least at 720p.
C4 works great with Roku and the C4 Mini-port driver so I can create direct links to YouTube TV in the Navigators (which you can't do with an Apple TV as there are no miniport drivers for it yet .. if ever).
However... I wish I could create Favorite Channels in YouTube TV like you can with Cable, Satellite and Broadcast sources... and my customers are starting to ask for that. It's probably a YouTube issue not a Roku or Control4 issue.