As far as I know the VMNG300 can do 100Mbps download but will struggle with the 10Mb upload something about 4 upload channels on the VMNG300, 8 upload channels on the superhub.
Free installation & superhub offers terms & conditions apply see
http://shop.virginmedia.com/broadband/up-to-100mb.html
Activation charge still applies though as far as I know.
I used to have the VMNG300 & going to the superhub added 2 miliseconds to my ping so not enough for me to complain. I used to get 8ms ping to Birmingham now I get 10ms.
on Speedtest.net the London (Namesco) and Paris servers are the only ones that can do upto 100Mb. the London (Namesco) server struggles to reach the 10Mb upload.