The trial is to assess wether new limits will more effectively stop heavy users from effecting the masses. Although with new limits on the weekend, it sounds like occational users will be hit aswell as die hard bandwidth hogs.
http://www.thinkbroadband.com/news/3872-preston-wigan-blackpool-in-virgin-media-stm-trial.html
Old traffic management scheme:
http://allyours.virginmedia.com/html/internet/traffic.html
http://www.virginmedia.com/help/traffic-management.php
Personally I've only noticed being managed once and probably only realised it was management not just poor service since I use a bandwidth monitoring tool found on the website in the top link (used for determining if I am getting close to the bandwidth caps, you can define your own trigger levels).
http://www.thinkbroadband.com/news/3872-preston-wigan-blackpool-in-virgin-media-stm-trial.html
Old traffic management scheme:
http://allyours.virginmedia.com/html/internet/traffic.html
http://www.virginmedia.com/help/traffic-management.php
Personally I've only noticed being managed once and probably only realised it was management not just poor service since I use a bandwidth monitoring tool found on the website in the top link (used for determining if I am getting close to the bandwidth caps, you can define your own trigger levels).