Looking at buying either new 06 B4s
Used 08 B83s
Which is the better ALL MOUNTAIN ski. I like to ski moguls, go fast, do some tree skiing and the groomers w/ the family.
Don't know too much about the '06 B4, but it's a pretty stiff, burly ski isn't it? I have the '06/07 B3 though (Same as 08, i think), and it's been a good quiver-or-one for washington. Good in soft snow, very stable in crud/refrozen/cut up snow, fine in bumps and not-too-tight trees. I've wished for a wider ski in steep, narrow terrain when there's more than 6" on new snow though. Not great on hard, icy snow. People complain about the dampness of them, but I like it for the conditions out here. I ski mostly off groomed stuff, and have the 176cm for 150lbs 5'10".
I have owned the 07 B4 & 07 B3. The B4 feels burly on groomers until you get to higher speed but is very easy to ski in soft stuff. It is more forgiving than the B3 and easier to slide around when necessary. It is a great crud & heavy powder ski.
The B3 is much better on groomers and adequate off-piste. It is a very easy ski to turn in all conditions. Where it really fell apart for me was in heavy snow. It was much too hooky and grabby. I've been told they addressed this problem in the B83 but I'm not sure if that's true or not.
I demo'd the B83 last year and found it to be the deadest ski's I've ever tried. I'd say it dampness might be good for fast groomer and/or crud skiing (especially in heavier Sierra/PNW snow but not for the CO snow I ski); however, it felt like it couldn't keep up with me in the trees or moguls.
P.S. - I believe the '06 B4 is essentially the same as the '05 B3's (i.e., 94mm under foot). If so, I friend of mine has them and he loves them (he's 150# and skis the 176cm which seems to be the perfect size for him). He says they are very stable, and damp but not dead, and he's definitely able to ski them fairly well/fast in tight trees, moguls, groomers, etc. as long as there's some soft snow.
to compare the B series, all you have to do is check the width under foot as they are the same ski at a range of widths. The B-4 is not a burly ski, it is not stiff or heavy. The burly ski in the B series (it is not reallly in the series at all) is the B-Squad, models 100 and 104 under foot, and it is a poor performer in moguls. That being said, go for the width that suits either what you like to ski, what you struggle with and need a ski to improve it, what you are going to ski most of the time do to your location.