My service drops by 75% exactly after I have downloaded 1200MB. I'm on the 10Mb service. This is crap! What can you do with 1200MB!!! Not much. The table from the Virgin website shows what happens at what times. I really hope it gets better soon as suggested when the 50Mb service comes online.
http://www.virginmedia.com/help/traffic-management.php
Updated traffic management policy
We’re making some changes to our traffic management policy. We think the overall impact will be that fewer people will be affected by the traffic management policy – but it’ll still make sure that use is fair for all our customers. Here’s the detail:
* Note: The upstream speed for some customers will be 200Kb. We are currently in the process of aligning this at 256Kb for all customers, and expect this to complete shortly.