I recently picked up a pair of B1 demos, a deal I couldn't refuse. Haven't ski's them yet, but they will be a third option for me this season, but have demo'd the x and xx.
The friend I picked them up from is sponsored by Rossi, and said that he prefers them to the B2 for all around skiing, especially if you like to carve, or for quick fall line turns. I had a chance to compare the flex of the B1 with the B2's at a local ski shop, and found that the B2's flexed like a wet noodle(slight exageration). The B1's flex was much stiffer, and seemed a lot beefier. I can't imagine these skis skiing similar at all, even though their construction is similar. Can something as soft as the B2 hold an edge decently on the groomers?....the above reviews seem to say so.
Judging by the flex, I would think that the B1's would make a better all around ski, unless soft snow is all around. Seems to me, that if you are 60% or more groomers, you might want to try the B1. If you are 60% or less groomers and ski in the west, then the B2's might do just fine. I will certainly demo the B2's this season, and agree with others that if you're looking for a one ski quiver, then demo, demo, demo. Just because one or two people say its crap, doesn't mean its not the ski for you.