Since nobody responded to my original post, I'll make a quick update.
Went up to Stevens yesterday with the gf to teach her and get back out there after a 3.5 week hiatus from the fall @ Whistler.
Pairing the 10/11 c02 ESTs with a 11/12 custom X was a cool combo. I felt 75% or so, therefore didn't push it hard but the bindings were manageable with some extra effort.
The difference between the cartel and the c02 was very very apparent, especially on mellow terrain. Perhaps it was lazy / unfocused riding while teaching + slowly building confidence, but I didn't really like them at first until I started really getting after it.
They were a solid pairing with the Custom X after I started working harder but jury is still out on these vs. the 11/12 cartels and overall experience. Those bindings and the Custom X seemed like a match made in heaven after about 7 days of riding.
Perhaps I'll grow to like the c02, but I think I'm willing to sacrifice some stiffness / performance for the softer flex of the cartel. I didn't try any ground tricks or ollies because I didn't want to fall and set myself back.