The burst thing is actually pretty cool. They're doing no more messing with their network than Telus is; any ISP has to throttle their bandwidth to the end client at some point. The burst thing they just relax the leading edge of the throttling. Telus' network is no more or less pure.
Shaw in Calgary anyway isn't messing with bittorrent (though I've heard it reported from other places). It's a thing of beauty when a torrent starts working at over 1 Megabyte per second
When they start messing with BT or shaping their traffic in that sort of way, then I'll really be in tough. Maybe wireless Internet.