They are cool but opened rarely.
Some are steeper than others and the scenery is spectacular. You do have to go with a group when they open and usualy accompanied by some sort of patroller or guide.
My advice, try for them for the sake of doing them then hit the trails like Cloudspin and Skyward while they are open. Every expert skier is looking to get to the slides when they are open. The rest of the black diamonds on the mountain ROCK when they are open.