In reply to Ysgo:
> Just seems quite limited use to me, as it doesn't look like it'll match the Phantom 6,000 or Spantik for warmth
Each to their own, and also for different purposes.
As stated already earlier, the ACrux is aimed at 4000m peaks. So Batura, Phatom Ultra/Guide/Tech are the main rivals.
Single boots are great, if you can get 'em dry during the night. But there are quite a few places, where you spend a few days in bivies and/or tent (I can think of quite a few locales in Norway and Sweden, but some routes in Alps also fit the bill). These are where a double boot shine.
And indeed, the lines does work with the rest of 'Ryx shoes.
What I'd preferred to see, would be them dynafit inserts. I know Scarpa made a limited run of old Phatom 6000s with them inserts. But from what I've heard, the time wasn't right. Maybe still isn't, but they would be quite nice on numerous locales.
I was half hoping that Salewa would offer something like that, now that they are in bed with Dynafit. But at least for this year it wasn't so.