Pros: Great lateral stability. Upright stance (saves the quads!). Moderately stiff flex.
Cons: None so far.
After 6 seasons of trying to get the *%&$@#$ things to fit right, I traded in my Lange X09's for a pair of Salomon Crossmax 10.0's -- were called X-Wave 10.0's last year.
Not only did they immediately fit better (and are easier to get in and out of) but the relatively upright stance is a great bonus -- I can ski longer without my quads burning out, and the upright stance is more suited for the carving techniques that work so well with the new shaped skis. No need to drive the fronts of the skis hard any more -- just "tip and roll."
These boots will work well for skiers
- at an advanced or expert level
- with neutral or knock-kneed legs (not bow-legged), and
- that like to ski all over the mountain (they're not quite full-race stiff, only about 15% less than the Salomon Course race boot).
My feet are a medium width overall, wider in the toe box (I can wiggle my toes!!) and narrow in the heel/ankle. I've got a good initial fit, but once the liners pack out, I may benefit from a custom liner. Of course, I immediately had a custom orthotic (footbed) made -- the stock ones are crap on most boots, and probably don't fit the biomechanics of your foot very closely.