Lost Simplicity
I had a Virgin TiVo for about a week before I handed it back. As an original TiVo customer I loved the simplicity, the crispness and easy of use of the original. The Virgin version is cluttered, confusing and displays random behavior that's just baffling.
Go in to the TV guide, and it won't start from the channel you're already on (it doesn't overlay like the original) but from random selection of channels.
If you have a Virgin TiVo you'll have the top package of channels, so to filter out the rubbish you can set favourites - which the TiVo will ignore and insist on showing you the whole list unless you select to view your favourites every single time you go in to the guide.
Watching back a programme and once it's finished the display will freeze. Or lose the sound. Or decide that BBC1 HD is an adult channel and demand your password.
If Virgin brought back the original interface, especially the wonderful EPG, remembered the channel you're on, remembered your preferences and generally got the software working it might be worth the £45 a month Virgin want for it.