I won't change the MAC on my PC - I can see that it works in Router Mode, but not Modem Mode and I shouldn't have to make changes like that to test things. I spoofed the PC's MAC to the Netgear router last night without success, but the same MAC was able to get 640Mbps in Router Mode before AND after doing that.
@ivixor - whilst technically true, it would be adding more WiFi signals to the area, adding to possible interference or bad signals for others in the immediate area. It also means reconfiguring DHCP and other things on the Hub3 to make everything compatible as my Netgear gives out DHCP addresses on the 192.168.1.x range, and the Hub won't change to that range, telling me there's an error with the address.
Hopefully someone from VM will see this topic in the next 24 hours and make contact, and if not then I'll try again with support. At least I'm still well within the 14 day cooling-off period and can go back to my original plan to move to BT's fibre-to-premesis offering that's not available from Virgin in this area yet.
Well if DHCP server randomly can get you a IP in modem mode in the same subnet as router mode that would be helpful yes but just having it jump around is good too should their be a subnet with rate limiting some where that could explain the slow speed.
One theory is VM for your area are making hubs in router mode have high priority or something like Non hub MAC's have a speed limit and that VM may review non hub MAC's and set them to higher speed at some point.