Electronic drums are not as quiet as you might think. Still a lot better than a real kit.
Drumming along like this can be hard as the drums would normally drive the song rather than the other way around. I think it is still a good workout for listening and building endurance. The display thing was interesting and I may try more of their videos.
!BEER
That is a good point about the drums driving the song. I wasn't really thinking of it that way. I guess it could be difficult.