It's missing a lot of decent features compared to the old V6 (and TiVo) boxes.
Some of the missing features are as follows; Wishlists (where you can set the box to record programs on certain subjects or featuring certain people), undelete, series link+, series link manager, suggestions, setting of series links for programs not in the current TV guide, ethernet control, keyboard support via USB, switching between tuners with constant buffering of all 6 tuners, skip-back on fast-forward, quickplay, default recording options, cancelling individual recordings from a series link, multi-channel series links, radio channels allowing recording of radio, separation of recordings between boxes, watching recordings when internet is not available and probably a few others I've forgotten.
Also, extra boxes do not have their own hard disks or tuners (unless converted from a V6 box), so you lose storage space and recording ability and are also reliant on the main box being on to watch and set recordings and also on having a decent wi-fi signal (or ethernet cable) between the two boxes when watching recordings.
The pooling of recordings between boxes is also a hassle if you have a multi-box system with independent users (such as older children living at home) as it means everyone's recordings get jumbled together, making it harder to find your recordings and if there happens to be a program both watch then if one person watches it and deletes it then it is gone for everyone (and can't be recovered because of the lack of undelete).
The fact that everyone is eventually being switched to the 360 was one of the main reasons I left Virgin earlier this year.
