Dennis, I have an Axiom 49, and it works perfectly with BIAB, Real Band, and PT. It has "semi-weighted" keys, the feel is DEFINITELY not "hammer graded" like a real piano (although the keys are molded to look like an acoustic keybed), but it is usable and I prefer it for modern music. About 9 lb. for the 49-key model. All the controller knobs and dials one could want. I use it in XP, so I cannot vouch for a Vista/BIAB/Axiom combi. M-Audio support is fair. There is a considerable amount of Axiom info on the net.

You might take a very good look at another board I use now -- the newer Yamaha KX series. I have the 49-key version. These are also MIDI controllers. I prefer the KX-49 to the Axiom in almost every way. Lighter (5 lb.? I think) but well made, looks nice, has ample controller knobs, etc. and although this is another "semi-weighted" keybed, it is quite pleasant to use.

Both boards have velocity settings, the Axiom also has aftertouch, which might be important for you. The Yamaha does not. It does, however, have an arppeggiator function built in.

In the $200-$300 MIDI controller price/feature range, I think these two boards are at the top of the pile.