If this was a problem with your router, why would many other VM customers be seeing the same problems all over the country, including those just using the Superhub and all kinds of different routers? An easy test is to try running some Youtube videos during the quiet periods, such as first thing in the morning. I bet you it will work perfectly with the RT-N66U in place. Oh, and make sure you're using a cat 5e or cat 6 cable between the router and the Superhub.
The problem is Virgin Media. In many areas, they simply took on too many customers and overloaded the segments. IIRC, they don't even flag up area upgrades until they get to 90 percent capacity, whereas most cable ISPs start upgrade cycles at 60 percent. This is just too slow when you've also got to get permission from councils to site new cabs or dig up roads.
VM tried to deal with this with a new Content Delivery Network (giant caches), but these had the same problems as the old transparent caches ie, they get overloaded, and are even slower when a cache miss occurs. They also had to put in loads of emergency bandwidth at LINX over Christmas. It's worth noting that the likes of BT have three times the bandwidth at LINX than Virgin Media.
I've always had good service, because I'm on one of the newest bits of VM network, just a few hops from LINX, and even I suffered stuttering/buffering Youtube videos during peak hours. VM just don't have the bandwidth necessary.
The reason for all this became apparent with the recent announcement of VM's sale to Liberty Media. The suspicion is that in order to make VM look good prior to sale, they'd been loading up new customers onto already overloaded segments, but reducing expenditure (ie not fixing and upgrading the network more than the minimum) in order to make the company look more profitable.
If the Liberty Media take over does get approved, VM should get more investment (it's basically been run as an outsourced debt management vehicle until now). It can't be worse than the current shower that's in charge.
