Yea we signed up for their starter package so we got free Tivo as well. We've not used it either, but that is mainly because we don't have room on the TV stand to put the box. So until we reshuffle the living room so the TV is on the wall and the hifi unit is underneath we won't be using it.
My only bug with Virgin TV is that you can't pick and choose the channels you want like you can with Sky, you have to upgrade your whole package to get more channels, and only the top one has all the HD channels :/.
Nomad, it's quite interesting that you can get FTTC but you can't get Virgin. Virgin is only FTTC and they run Copper Cable to the premises and into the Superhub and Tivo box. AFAIK BT are the only people who can do FTTP, but I suspect that some commercial companies may be able to do it as well.