Wave - From some of the shop folks I've talked to, and I think from a comment I read on an Epic thread, K2 brought money/stability, but not design influence. That's all second (3rd, 5th???) hand, but logically, the Line line (hehe) brings a "different side of the spectrum" product to K2. They have their standard heavy stable damp products and with Line, they have a lighter, fun and more responsive line-up.
monologuist - Yep, I know you have been concerned about the 100 being "hooky", and yesterday in some "Colorado" heavy crud (NOT Sierra cement...), I kept wondering how to reply to your questions about that. My wife demo'ed some Volkl Cosmo's yesterday so we spent a lot of chairlift time talking about her demos and my P-100's. After a late morning run (Copper Mountain) on a big steep southfacing slope with the previously mentioned snow condiditons, I was trying to decide why I had trouble and so my mind jumped on "hooky". But truthfully, I could not explain what "hooky" meant to her. They are carvy, and in deep heavy broken up snow, you can over-drive the turn and get your weight thrown a bit forward. As you (over) correct that and spin them around, they can come around real quickly. Results in a bit of a hurky-jerky ride, which isn't pleasant when you have that kind of snow. My old K2 Outlaws would have been tamer, damper and plowed through that easier.
So I started paying attention to how I was skiing and I "slowed down" or eased up on how hard I was driving the turns in that snow, and the ski's settled down and did fine. So I'm thinking they can over-react and be considered "hooky"??? Maybe all those folks that didn't like them were used to stiffer, longer radius, damper skis... Make sense?