Okay, so i was getting packet loss after recently upgrading to the superhub4 and Gig1 service. Every game would lag and quite frankly was a massive pain, this would also obviously affect twitch and any other online service. I see a lot is having the same issue. I decided to try and turn off the Firewall on the router and surprise surprise, no packet loss.
Now obviously you do this at your own risk, but for me i'd rather have lag free gaming.
If this fixes it for you then please comment below, let Virgin know how subpar their hardware is rather then blaming it on everything but the router.