Ok, I'm happier now. Removing the downbridle decreased pull in gusts considerably, without comprimising low wind performance or speed (as far as I could tell). Hooked my lines up to the outer bridle points, and the kite was flying really well.
It definately does not fly like a Rev I or a Rev II, but is still lots of fun. The power and the speed (and the accompanying noise) is great. It's also a total workout to keep the kite moving, and not crashing. If you hold the kite still, or take it to the top, or sides of the window, it wil hang there, and not pull much at all. With almost no wind, I was able to float the kite back and forth across the window, and even do a few spins. The ability to jerk the lines when the kite falls flat on the ground is great as well. With a conventional Rev, you are stuck trying to carry the kite and lines back to your stake, or running to grab your stake and hoping the kite doesn't blow away.
All in all I like the Blast. It does not fly like a conventional Rev, but has its pluses. I think a 1.5 SLE is in my future. Will the 1.5 be ok with the Blast or the II handles? I already have three linesets. (150x85, 200x100, 80x75). Is the low wind performance of a 1.5 as good as the Blast? Can I put a regular leading edge in a 1.5 to keep the weight down in low wind?