Hi Tim, the arms are held closer together when you install them.
Hi Chris, this is the only option. It works well though; he'll get used to it quickly.
Hi Tom, please note there was a good amount of rocker in the 2015/16 edition (also the one Trace is skiing), but that has largely disappeared in the newer version. The choppy snow is probably a touch easier with the rocker for most folks, and the running length will be a longer with the later edition. There seems to be a little more pop when skinning vs other race skis because of the camber, and the balance is largely determined by where you mount them.
Hi Michael, that is a decent match and is a good entry to tech bindings (not least because of the ease of said entry). The 100mm is the right brake size and the precut skins work great!
Hi Sam, looks like you found them. They are listed as Radical Crampon Receptors.