Thanks for posting, though sorry to see that you've had some connection issues. I've run a few checks on your service and both your Hub and local network segment look in good shape, so the slow speeds are something of a mystery, how are you connected wired or wireless?
A wired test with the Hub in modem mode would be helpful if issues are still ongoing.
It turns out that this issue is on going for the majority in my area, while you say there's no known issues, it's apparently down to 'over subscription/over utilisation'.
The tests shown above were done via a wireless router of course however I have also run tests directly with the Ethernet connection. The speed is slightly increased but we're talking 10MB tops. (at non-busy periods, i.e 3am) Ironically I do pay for 'upto' 70mb. while the speeds were previously almost achievable (usually average around 30-50). it's now consistently dropping to the speeds above during busy & non-busy periods.
I have discussed the above with virgin directly who have refused to acknowledge there is any other issue other than over subscription as mentioned above.
Interestingly I did post this on a public thread with good old Facebook to see the results others in my area were having and the only people who were not having similar issues were not using Virgin provided Hubs. I know this doesn't help any however if you have any hints as to the mystery it would be much appreciated.