Plus, peering can change, as I witness all the time with Frontier out here. Can be problem-free for months, and then one day the buffering starts. Sometimes, albeit rarely, I am unable to watch anything at all.
EDIT: A good example - I just did a tracert from local to remote, and this time it went straight from my CA ISP to a hop in New Jersey. Never seen that before. Normally, it goes L.A. -> San Jose -> Chicago, Beauharnois.