Just signed up with Spark after a few years of not bothering with Bein/Sky. Really pleased with what I've seen so far. Watched the build up show and F1 Grand Prix last night/this morning. It never buffered once and the picture was clear the whole time. This was just on my computer - didn't cast it to a TV etc.
I think one of the friendly games that they have on there was available to watch on demand about 10mins after the game finished (but I wasn't paying the closest of attention so might have that wrong).
Really looking forward to the season starting now.