I don't know what the dynastours are like, but i have a pair of b2s and i think they are great. Come from a racing backround, and I ride pretty hard (need dins at 9.5+ or they fall off). I think they hold an edge at high speeds quite well. They aren't a GS ski by any means, but that isn't what you want. I think they rock in all kinds of groomed, crud, and aren't too bad in the pow. and they have a bit of a lip on the back too if you want to mess around a bit with the switch landings and stuff (still no tts tho)
hope that helps a bit!?