Benoire:
It seems like it will be similar to the other internet distributed sports; poor usability. Netflix et al. have got around this by thumbnails and can generate them prior to release but live sport doesn't have that benefit as its live and you need to keep the data flowing. Meh I was happy with DVB-T/S as it offers a good picture with advantages of local recording etc. for skipping around easily, but to be honest I'm not a fan of internet distributed TV content anyway.
Here's a radical idea. How about waiting until you can try the service before deciding how usable it is?
N