I've also been having these exact issues for weeks now. I finally had enough and decided to contact Comcast this past weekend. Of course, being on the weekend, I knew from the start that I wouldn't get a representative who could actually help me, but none the less, after dealing with one of the desk employees, I managed to get them to elevate the ticket.

I received a call yesterday from someone in their routing department and he told me that he would keep the ticket on standby, but that if the packet loss occurred after the fourth hop (outside of Comcast's domain), they could not do anything about it. I told him that the packet loss mostly occurs at the fifth hop, which is the first Level3 server I get hopped to, and asked who I should contact to push this issue further along. He told me that I would have to talk to the game developer (SE) or the "website", which I'm assuming he meant Level3.

What I'm guessing is that I did not get quite high enough on up their chain. I'm going to try to re-open the ticket tomorrow and see if I can get it elevated higher.

Unfortunately, the last couple of times I've tried WTFast, it hasn't actually helped. In fact, in some cases, it's made it worse, making me think that the default route they set up for me isn't actually bypassing the problems.

It's a real shame this is happening, and that the "solution" has to be so complex, if even possible.