These responses are a perfect example of where my puzzlement comes from.
There is a significant number of BPL'ers that clearly appreciate the flexibility, control, and fun provided by AT gear. Yet, the BPL community, in general, has been all about more hiking than "camping", more into weight savings for the joy of the trip than the accessories for the joy of the destination.
It seems to me that AT gear is more the accessories for the joy of the destination. Awesome for what it is and what it does, but not light and fast? . . . I watched some snowshoers pass a couple on AT skis on rolling terrain last weekend.
I cannot imagine that AT gear is nearly as light as lightweight backcountry gear. I cannot imagine that rigid plastic boots are nearly as efficient as lighter, more flexible backcountry boots for traveling across anything except the steepest terrain.
. . . but, is my imagination flawed? Is the stiffer, more stable and heaver AT gear really faster than backcountry gear, off track in most situations. Or, is this just an inconsistency in the BPL community where many members love the thrill of doing turns at the sacrifice of speed and distance?
I want to have fun traveling through the winter landscape, for 1-10 days, (mostly Oregon/Washington Cascades) which will surely include lots of rolling terrain, lots of steepish (mostly <30 degree) side hills, a little bit of climbing steeper trails/switchbacks (maybe 20-30 degrees) and certainly a rare stupid climb onto some mountain or ridge-line I have no business being on with the gear I have.
Will I be sorry if my boots are too light and flexible, or will I just travel further and faster while being less able to manage technical terrain? And, how frequently will I be sorry because I am sinking on a 70 mm ski when I could be moving much better on something much wider?