Never skiing a traditional alpine boot again. Although I may get a beefier non-race ski mo model, the low weight, incredible range of motion in walk mode, super slick one lever transition to ski mode, and just as rigid (as I've ever skied) as an alpine boot, and I see no reason to use a "normal" boot even for resorts.
Prior to buying these I used a pair of Scarpa Matrix and Scarpa F1's for skinning. Both gave me either hot spots on the shin or near the ankle. Neither had great motion but it was what I knew so I really didn't know.
Specific to skinning up and the little ski mo racing I recently did, they continue to amaze. The flexibility makes the one choice post on the dynafit low tech bindings I chose (PDG skis also) completely adequate in all but the steepest pitches. Paired with a pair of stirrup pants with cut outs, they feel just as comfortable and secure in uphill mode as my Nordic skate boots and not all that much heavier.
They are a bit narrow as I have a somewhat wide toe box. I was already having some nerve pain in my toe prior with my bike shoes in summer and they aggravate it a bit, but nothing that a boot fitter, a metatarsal pad, and a bump out can't fix. They didn't cause it. Just reminded me that solid non-flexing soles aggravate what I already had. However, this was after skiing them in a ski mo race in the AM and then all day after skiing with my wife. Foot likely a bit swollen from a long day in them. They are surprisingly comfortable for such a minimal boot though.
As for downhill, they lock seamlessly and are super solid. As an avid Nordic racer, my bar for support is low, so please take that caveat. I'm used to opening it up with a lot less. So this boot with a locked in heel makes me feel unstoppable on fast groomers. On anything else, it's user error. My skills in hard snow black moguls, trees, and chutes is mediocre at best.
In a nut shell, I ski as well in these as I DID (seriously I'm NOT going back!) in my traditional alpine boots.
Thanks also to the staff whom I called when I got these. They felt tight so he walked me through it all on the phone. They've "packed out" as promised and are quite comfortable.