They have a live feed, but it is mostly just a loop of "news" clips with periodic summary videos as the test goes on. Nothing worth tuning in live for, IMHO.
Yea, the offseason doesn't provide much in the realm of the live feeds for the major tests. But the periodic videos they post are pretty good. Pays for itself during the actual season, though......
It's been remarkably consistent for me. Last season was the first time I watch races using the live video feed. I pull up the app on my iPhone, start the stream, and then cast it to my AppleTV on the big screen. Perfectly acceptable HD quality and not once during the season did I have a drop in signal or lose the connection. Being able to stream the videos after the fact from anywhere/anytime is just icing on the cake.