First of all as a video memento of a snow trip with friends this would be epic. Some amazing shots in there, some of the transitional shots are amazing, beautifully shot slow mo magic, some cool boarding reflected in the goggle moments and having fun with friends on and off the snow to some well selected tunes.
However to reiterate the points of others, too long, too much. The opening is cool and very professional but then drags, this trend then continues.. Go pro is tough to get right, some shots are cool regardless of ability and lack of tricks, I'm not an advanced rider so enjoyed and appreciated some sections but you are editing so you should make it as cool and interesting as possible. But shots of just ski's or looking at yourself or rider at the time are not interesting to your average viewer and there are a lot of these.
I think if you shortened this up, tried a few things as riders (little jumps, kickers and spins) even if you fail it's funny and will look cool with your production skills. If you are going to tell a story, tell the whole story; the new, the fails, powdery terrain, the moments of magic for you guys on the slopes. Instead it was some cool editing with some very safe and simple riding.
Best thing I found making videos is that if you are in them let somebody else who isn't edit it with you, they will chop the dull and appreciate the cool.
Very cool overall, look forward to seeing the edited down version or your next attempt... What editing software did you use??