If you use a good player with a good adaptation algorithm, it will not switch from 720p to 240p ... of course poor players will do that. But a good player implementation will rather switch from 720p @ 3 Mbps to 720p @ 1.5 Mbps if the bandwidth decreases ... so the quality difference is really limited but the video continues to play without a problem. we've a lot of demos where you can try it out yourself at http://www.dash-player.com/demo as well as http://www.bitcodin.com/live-streaming/