Virgin are complete, utter prats
Had their adsl service for a while, while it was still actually virgin, rather than rebrandedNTHell, and it was ok, 512k @ 4km from the exchange, I knew no better and it at least stayed up 24/7 (except once every month when they renewed the IP address, apparently by powercycling most of their servers, a process taking 2 hours or more)
Then NTL got involved. Immediately the network was connected to transparent proxies without permission, which didn't work anyway. Once I complained, the adsl disconnected, reconnected, disconnected, etc. ad infinitum. They claimed there was 'an issue' (no sh*t!) and their best engineers were working on the problem. After 2 weeks of calls to the premium rate customer service line, I told them if their best engineers couldn't fix a very reproducible (ever 10 minutes, ON THE DOT) problem, I was gone. A 'retentions' creature tried to tell me it was to do with their throttling and all isps did throttling and transparent proxying. So I found me an ISP who do neither*. It costs 3x as much, but you get what you pay for, and despite a few troubles with servers dying (which they're honest about and don't get some chap in India to make you reboot), I haven't really looked back.
As a backup for those times there IS a problem, I contacted virgin media (2 years after disconnecting from their adsl) to see about getting this wonderful fibre optic broadband, as a redundant connection with the decent isp*'s ADSL. Apparently, despite everyone round here having cable tv, AND the cabinets being everywhere, we're "Not in a cabled area". So I asked the salescritter what the green cabinets were. Apparently they're BT's... I said "no, one of them's open, BT don't do cable tv, can I speak to someone who knows something about your network please".
Apparently there was nobody working there who knew about their network. That may be closer to the truth than they'd like to admit. After several attempts, I found someone with a vague clue, who informed me that "not in a cabled area" is shorthand for "not on digital cable" because some of the reps apparently are too thick to know that you can have cable which isn't digital.
All in all, if virgin media went down the toilet, nobody would (a) notice or (b) care.
*webtapestry. Helpful, knoweledgeable, efficient, a bit pricy compared to 'consumer' isps, but worth it.