I have been skiing on the 9.12's (150's) virtually all year and I have never had such a blast in 30 years of skiing. I purchased them for club racing for my very first try racing but them started using them everywhere. Steeps, icy chutes, bumps, wind blown and the occasional knee deep stuff in Kicking Horse. With dimensions of 115-65-100 is has a very versitile shape. I also really love the fact that when I hit the occasional ice, I just keep on carving instead of skidding through it all. You also don't have to just make short turns. In fact it will go straight and do GS turns, just don't edge it so much. Now, I wouln't use it for making GS turns while heli skiing but that is about it.
I was told by an Atomic rep that the SL 9 just has different cosmetics and a new 3 piece riser but should ski basically the same. I tested the SL 11 in a 164 (i think). It has extra metal in it for added stiffness and I found it to be very quick. I can't comment on it's off piste performance however.
I have several friends who are now looking for the 9.12 for next year and I would love to find a pair of 160's as my all mountain ski's for next year since I have trashed my edges on the 150's down some chutes with not quite enough snow. I might try to mount some Randonee bindings this spring for some backcountry action. A 150 cm ski would be great for hiking up the trails with and not snagging on the trees and brush.
I have never skied the 9.16's.