One hell of a difference. I'm pretty shocked that they're doing this. I always thought it was Youtube that was being slow. http://www.youtube.com/watch?v=CB8UADuVM5A is an accurate depiction of what I just experienced right now.
I've never been able to watch anything in 1080 or 720 unless I want to go run an errand while it's loading.
After running these commands...1080 streaming like a boss.
I also applied the trick and now, magically, everything is quite a bit faster.
That said, while I'm not a network guy, this suggests that there's an issue with the YouTube CDN, not anything in particular with Time Warner or Verizon, unless they're doing something horrible relating to net neutrality.
My guess is just that there are a couple of CDN blocks that are preferred by the load balancers and they're saturated as a result, and blocking these IP ranges sends you to a less balanced block of CDNs.