From Frisco Breck is super easy. There's a bus that runs every half or hour depending on time of day. That bus also runs until 2 am so you can take it into Breck to enjoy the restaurant/bars and not have to worry about driving. I can't remember if you can get to Vail directly from Frisco without a car. You can get to Abasin, Keystone and Copper all from Frisco via the summit stage which is free.
Vail probably will have more "expert" terrain open by acreage but much of that is the bowls which can be great fun but are by no means challenging terrain. Breck tries to get the Horseshoe bowl open by Xmas which offers some shots that are significantly more challenging than the terrain what will likely be open at Vail. This is of course all snow dependent. If you aren't set on a hostel I would look into the snowshoe motel in Frisco. Their rooms usually run around $70 a...
Search Birds of Prey downhill. The race is on golden eagle (the run being discussed) and is typically the first downhill race on the world cup circuit every year. The steepest section is called the brink.Compared to most of the other runs being discussed on here the pitch and exlosure is not really that bad, what makes it different is they water inject the surface to make it harder and more consistent for the racers. Its basically an intentionally created ice sheet.
I was skiing that a couple years ago, crashed and couldn't stop sliding. It got to the point where I was sliding like .5 mph, barely moving, but still couldn't stop it was more comical than scary but still gave me an appreciation for what happens when they crash at speed on that course.
You missed the second half of my comment, I was joking. I have never seen a checkpoint for going down. Also not to start a 4x4 debate but it doesn't do anything for you going down. A 2 wheel drive and 4x4 are just as likely to slide off going downhill given equal tires. All cars break with all 4 wheels
Yes make sure that you bring blankets and water because they won't let you on the road down and they will quickly run out of hotel rooms up there. In all seriousness if you get up they won't give you grief coming down the mountain. I don't live there but have done several trips with just FWD rentals up there and as long as we got up never had an issues about us coming down.