Have you tried different speedtest.net servers?

Say London, France & The Netherlands?

Line is running at the estimates, which meets the sales patter.

Issue is actual throughput, and as such the time of day you are running the tests is very important, as is testing to various different locations.

If it is slow at even off peak times, then do things like avoid using wireless, i.e. plug in using a cable, and also check the PC is optimised for these sorts of speeds at www.dslreports.com/tweaks

Just to show a balanced view of Virgin cable, here is a speedtest showing a comparison of my (up to) 10Mb Virgin line (£26 a month) and a BT ADSL line (my employer pays for this so I don't know the cost).

The download speed may be slightly better, but the upload is worse than the ADSL and streaming 3 episodes of Eastenders in HD through iPlayer will cause throttling to kick in.

On the plus side, it has been pretty reliable.

http://www.speedtest.net/result/1618158767.png
http://www.speedtest.net/result/1618157195.png

In reply to a post by Anonymous:

Connection Speed 15946 kbps 1098 kbps
Line Attenuation 26.0 dB 15.1 dB
Noise Margin 7.1 dB 7.6 dB

You're actually getting 16Mbps so I don't think you have anything to complain about.