"keystone has some of the best glade skiing ever"
keystone was one of my favorite places to ski/snowboard all of the runs are marked what they actually are the entire run. so when you ride a black diamond its a black diamond until it meets up with a blue at the bottom. great place for super huge carves all the the way down. also the glade skiing was some of the best ive ever had, its up there with vail as long as you dont mind hiking a few hundred yards to find fresh lines and waist deep powder that is untouched. my only prob with keystone is that the only way to get to the bowls is hiking, snowmobile, or cat.... but you can buy beer all over the place on the mountain and its fairly easy to get around anywhere you want by taking certain chair lifts to the various peaks.
you also get a great 360 degree view and a really cool view of breckenridge. (see pic ) one thing to watch out for though is when glade skiing on anything near the "black forest" by the north bowl it bottoms out into a creek/lake bed so if your on a snowboard its hard to keep your speed up and if your unlucky (like me) you might have to hike a while to get out , but its worth it! very untouched lines and super cool chutes so my tip is stay to the left as much as you can as you go down as to be heading more towards the chair lift then away from it (so every time you think of going left or right by a tree go left as much as possible to avoid this on this particuar part of the mountian)