tight pitch

I'm not completely sure, but from what I've read on his site and in discussions he's had with others, Andrew used the silnylon Solomid because he'd had prior experience with it and could vouch for its reliability, and going out to a place as remote and wild as northern Alaska and Canada required something he could absolutely trust. I've also heard that silnylon deals with snow loads better, since the snow slides off more easily. A lot of people when going to the north or traveling a long time alone use yellow to pick up their spirit when it's raining for days on end, and also to more easily find their shelter from afar when venturing away from camp.

Cuben is definitely worth it and can handle the conditions (Ryan Jordan, Roman Dial, and Jason Geck used two cuben pyramid shelters in the Arctic 1000 walk and they worked very well), but you have to be a little more careful with it, and from what some users say when it fails it fails catastrophically, whereas silnylon is more forgiving.