The biggest difference is that the gopro HD will shoot 60fps which means you can slow your footage down and it will remain smooth. You can also use the backpack accesories with the hd hero and you can't with the 960.
the 1080 has the ability to shoot 760 at 60 fps, which is sick if you want to do some slow-mo. But if i were you i'd save 50 bucks and use that money to go buy a lift ticket somewhere else rad and film that for a day.
I filmed all season on a 960, loved it
"I hate when people mistake park rats for skiers."
"my parents got my report card yesterday and now i cant use my new skis and they are taking away everything (ski related) they bought for me."
This thread should tell you everything you need to know plus gives you a visual idea- I know TGR is sacrelig to some on here, but it seems pertinent enough in this case... I was having the same debate so I've been doing similar research