Pros: performance; comfort; durability; warmth; not a dedicated telemark boot
Cons: poor insoles; not a dedicated telemark boor (if that is what you are looking for)
My everyday skiing is off-trail x-country through rolling terrain (with the occasional steep climb and decent). Although I appreciate 75mm telemark equipment when I truly need it; I find it agonizingly inefficient compared to NNNBC for most of the skiing I do. If there was more vertical in my backyard- I would be in 75mm nordic/telemark gear.
In recent years, I have struggled to find the perfect NNNBC boot. I have tried the Rossi BC line; like it; but not enough support. I used the Fischer BCX6 for two seasons; love the performance; but they hurt my feet. The Fischers' flex point squeezes my toes and metatarsus.
So far; the Alpina Alaska is the best NNNBC boot I have tried. Incredible comfort; impressive support; excellent stability; excellent stride and glide.
I am currently using this boot with NNNBC magnum bindings; Madshus Eon and Annum skis.
I now have more than 1000 kilometres in these boots. The comfort and support continue to impress me. As far as performance; these boots excel at what hey are designed to be: a heavy-duty, off-trail, kick and glide x-country boot. They stride and glide beautifully.
As far as downhill performance; despite how burly they are- snow conditions can severely limit what you can do in this boot. Now I realize that this is also partly due to the limitations of a NNNBC binding (versus a 75mm tele). But if the snow is hard-packed, and/or there is a thick crust; this boot is not strong enough to adequately steer a ski in a telemark turn.
However; if the snow is soft; I have consistently managed to steer some sweet tele turns; even on the Madshus Annum (109mm-78mm-95mm). I really don't think that a 75mm telemark binding would make that much of a difference. If the terrain and snow conditions require a lot of rigid strength to turn the ski; the boot will fail (this boot is designed for striding; not steering).
However; this boot is perfect for my everyday skiing: off-trail, backcountry, kick and glide, xcountry. And for that; the NNNBC binding is a perfect mate. When the snow conditions are too harsh; I simply am a bit more strategic with my descents.
Durability: after more than 1000 kilometers. Overall, durability is impressive. The standard insoles are inadequate; they have little support and they gradually slide back as you ski. The lace system is excellent; however the cleats are hard on the laces. The cleats, coupled with no lace cover; cause the laces to wear. I would definitely recommend bringing an extra set of laces if you were headed out for a multi-day trip.
Also- and perhaps this goes without saying- treat the leather- thoroughly. I am using Zamberlan Hydrobloc. I thoroughly wet the leather before applying the Hydrobloc; for complete saturation.
Out of the box these boots are more orange than red. Once you treat the leather- they will turn red.