I am with Virgin for TV, broadband, phone and mobile. We are connected via fibre and most of the time the service is good. I have a headline connection speed of 10 Mb and when I have tested it in the past I have had good speeds reported: Better than 9 Mb.
However I have also had results like this reported:
http://i.snag.gy/TAOju.jpg
I have had patchy service from Virgin from time-to-time: There have been three occasions when I thought that I might start looking around for another provider. The most recent was Summer last year.
In summary I would say that I am happy with Virgin's service. It could be better but I guess you could say that about most providers?