Thanks for the info Mark
I was trying to set a limit on Youtube a few weeks back so it wouldn't interfere at all with a 64Kbps audio stream (the whole reason for Snap as a back-up). I use www.softperfect.com Bandwidth Manager for this and to pass TCP ACK packets without queuing to stop uploads screwing up downloads. Although I think by the looks of things @ your end it bursts to buffer then slows down Youtube anyway to only what's needed?
I was trying a whole host of IP ranges including the TCL one's to try and limit Youtube to 1.2mbps (enough for 360p) but I wasn't have any success and gave up on it after after entering countless IP's willy nilly from netstat observances. So I'll go try that range instead.