So my two cents.
Finally got out for the first time on my ProtoCT 157. First time riding this year and first time in new board, bindings (Burton Prophecy Reflex) and boots (K2 T1). Conditions were less than good, man-made packed base and temps in the mid-40's. I spent my first 3-4 runs just trying to get back in the swing of riding after 9 months off. I had to adjust to a longer board (I rode a 2009 155 SL the last few years), a longer effective edge, and a centered stance. I absolutely noticed the longer effective edge more than anything. It seemed that it took far less effort to initiate a turn and when I did, the edges just locked in. Likewise, transitioning in and out of turns, it felt like it took more effort to disengage the edges, especially in the tail. Not sure quite how to explain it but frequently on the first few runs it felt like the tail was still holding an edge much longer than I wanted/anticipated.
It wasn't until my 2nd set of runs, after a two-beer break, that I felt like I started to get a good feel for how to handle the board. I'm not able to break things down into technical terms like some of the others here, I just know that suddenly the discomfort was gone and the board was an extension of my body. I thought about it and laser fast, the board was doing it. Edge hold was great at moderate speeds (first day out, I didn't bomb much of anything just cruised), very fast edge-to-edge, very playful but it still felt substantial between my feet and could handle the poor choppy and hard-packed conditions. I did notice the board has quite a bit of pop, more so than my SL. I didn't really push this, hitting jumps or trying to load it up, this was again mostly just cruising around and testing out the board and doing small ollies and playing around. When I got my timing right, it felt like the board just wanted to leap up off the snow and keep going up.
Unfortunately due to other commitments (stupid responsibilities) I had to cut it short after the 2nd set of runs. I'm going back out this weekend and the following weekend road tripping to Seven Springs. After those two weekends, I should have a much more well formed opinion of the ProtoCT. Based upon the 2nd half of my first day out, I absolutely am confident this board is going to live up to my expectations.