Thanks for the replies.
The Look/Rossi lifters are not connected, so there won't be any negative effect to the functioning of the Autodrive system.
I've not been much of a gearhead since the 80's when I worked in a ski shop during college. Hence, I bought my son the SC9's based on:
1) I've been on Dynastars for nearly 20 years, and they've served me well. I haven't tried much else since the late 80's, but I used to demo a lot during my college days. Settled on and loved the Course SL's for years. Currently on some fairly beat-up Speed SX's that have done well, though they're a real handful in powder with their 62 mm waist. Been buying kids skis rather than my own the past few years (I have 3 boys who ski). Maybe next year will be my turn
2) Poking around the internet a bit, it seemed the SC's made sense as an all-around ski with a major concern being performance in the bumps at Mary Jane. The SC10 is what I'm interested in for myself, but I was concerned his 150 lb. frame might not need quite as much stiffness as my 200 lb. frame. The SC9 has a 69 mm waist, and I was concerned that something much wider might become a detriment for us in the bumps. Maybe I'm wrong?
3) The kid is REALLY hard on skis, so I'm not about to spend big $$ on skis for him. The SC9's were cheap enough that I'll be satisfied if they last him 2 seasons. They should be a big step up from the crappy Salomon X-Free 8's he's endured the past 2 seasons (what can I say.... they were a mismatched set that had been misdrilled at the shop. $40 bucks later, I had him on new boards to replace the one's he'd delaminated. I'm amazed they're still intact after 2 seasons!)
Back to the lifter issue... I'm concerned about too much lift becoming a detriment in the bumps, and I'm also concerned about the reduced stability while descending technical sections (steeps, rock outcroppings, etc.) We really don't spend much time on groomers, so I don't really care about that.
REI has two binding candidates on sale... Look P10 lifter (his DIN is only 6, so it's enough binding) or a Rossi Axial 110 with no lifter. I was all set on getting the Rossi, but I noticed many sellers packaging the SC9 with the Look lifter binding. Hence, my confusion
Thanks again. I'm still pondering.