Gotta say it ain't as good as it sounds.
OK i don't have virgin BB but i do have BT.
I tried to get sky and was told that the speed would be the same as BT - it wasn't not by a long shot.
Then i was told that my line (fibre optic) was to old for sky BT and would have to have a copper sheath put onto the line to allow the BB to work.
SKY wouldn't pay for this as it was not up to them to provide the proper line.
the customer service i recieved was very poor and nobody seemed to care - all they wanted was the business but it would be up to the customer to sort it out.
MY opinion is don't go with sky but there could be others that say sky is great. (ps i am a sky customer for TV so i ain't completely anti sky - just the BB caused me problems)
HTH
TFB