Just got back from a mid-Dec trip to Niseko where we got massive dumpage. It was unreal. At times it was mid-shin deep on the "groomers".
I rode my Gnu Carbon Credit 153 (I weigh 65.5kg w/o gear, 5'10" height) and wished for something with more float in the deep pow. Rear leg burn like mad. The magnetraction also caused some drag in the pow.
I'm now shopping for more pow-specific board for my next trip there in Feb.
While I was there I rode a friend's Nidecker Ultralight 158 and that board was mindblowing for the conditions. Fast, quick edge to edge, float in the pow... it was just magic.
Sorry I'm not familiar with the boards you listed, but I'm currently looking at the Nidecker Megalight & Ultralight, Yes Pick Your Line and Rossignol Experience.