I've been using Channels for about a month with an HDHomeRun device. It was a bit rocky at first but that was all on HDHomeRun as the problems existed on all streaming apps, even HDHomeRuns. The Channels DVR has some issues, but it working generally well now.
I just (today) subscribed to Sling Orange...primarily for ESPN with the expectation that I'd use its TVE stream to DVR games with Channels.
When I added my Sling account to Channels, it finds 62 channels, but no ESPN. I've verified that I can sing into espn.com/watch using the Sling credentials. Why is Channels unable access ESPN. It isn't even in the list of channels.