This company is a nightmare, here are my experiences to date.

Bandwidth throttling seems to happen on random things.

On the sword 2 client downloading, its taken me three days thanks to this ridiculous decision. Yes its a torrent but yes its from an established company that realises the speed torrents can actually provided.
http://www.gamersfirst.com/sword2/

Bandwidth Throttling in second life, not a torrent. This took the biscuit. I can get near 300-500 downloading speed while running either of these two services elsewhere. I can get this speed on them in the morning but come 2-10pm Virgin throttle the bandwidth to nothing, literally nothing, its not slow its anything from 0-20. Then they actually disconnect my router from their network till a few minutes have passed in some kind of fun game? Over and Over again when I try to use these services.

This only happens while I am using certain services, torrents or second life for instance, otherwise things run at acceptable speeds, even alongside them. Other random things that virgin have in some draconian manner decided bad are throttled as well, but these stand out in recent experience.

There are other decisions they are making to become a more draconian ISP, such as selling our browsing data? I cannot confirm this but after all this I wouldn't be surprised.
http://www.badphorm.co.uk/page.php?2

Now they are banning sites as well, deciding what I can and cannot do in a service I have paid them for. This almost makes me laugh.

In closing like AOL once did when they had too many problems all at once, Virgin have lost me for life.