In summary - I hope
It doesn't look like I will have a chance to demo either of these skis early on in the season but I want to get off my old skis ASAP so I will make the plunge sight unseen so to speak.
I want a ski that will allow short, quick turns but be stable in long carves. One that will be good on groomers and off-piste in heavier west coast snow and crud. The right length for my size - 6'1" about 220 lbs. Remembering that I am a fairly strong advanced skier but not an expert.
I think that I could handle the B5 and it would probably teach me a lot about modern techniques coupled with some good lessons. I do have concerns that it may be much more demanding than the M11B5 and be more unforgiving of some of my old habits.
So all considered I am going to go with the M11B5s in the 176 length. (Maybe I could just never quite forget Phils definite beliefs
.) When the demo gear arrives at the hill I'll try and get on a pair of B5s and see how they feel. Maybe the whole process will be a two step deal if I find that the B5's can offer me something else and next year will be the time for the B5s or else the new M11B5EX that Atomic will be bringing out for '08. You have to admit that a ski designated 5EX has a certain 'je ne sais pas' appeal
Thanks to everyone for the invaluable input and I will let you all know how they work out. Two months 'till opening day!!!