I’ve been watching some League of Legends gamecasts, live video. They offer several streams including Twitch.tv and Youtube. Here’s the bandwidth for a 720p stream; from Twitch first (a steady 2500kbps) and then YouTube (variable, averages 1600kbps). My network caps out about 6000kbps.
It’s great that YouTube uses so much less bandwidth, but I’ve had real problems with reliability. In San Francisco it’s nearly unwatchable on WiFi. And in Grass Valley with the 2500kbps burst to 800kbps sustain network, YouTube’s stupid bandwidth estimator gets all confused by the burst and fails to deliver a reliable stream (at any quality). In general I think YouTube is trying to be too clever. That sawtooth pattern is sure weird.