What's really changed at Breckenridge since you were last there is the expert terrain. I'm not sure how to interpret your classifying yourself as advanced. Much of our expert terrain is around or in excess of 40 degrees and sustained steeps at that. So, if that's what you are able and interested in skiing, here's a bit of a view of our terrain.
Possibly our most notable terrain is our high alpine steeps. These are on Peak 6 (particularly off of the hike above the Kendo lift -- hike looker's left into Six Senses and beyond to peak 6.5), the upper part of peak 7 (particularly CJ's, Sadie, Tele, Arte's Bowle, and the Y Chutes), the Lake Chutes and Horseshoe Bowl off of Peak 8. The Lake Chutes are also a hike, and have lines within them that top 59 degrees. They also have rock bands and can be quite dangerous.
Off of peak 9 we have some great tree skiing in the windows and Doors. If you are a true expert, eye of the needle can be interesting but it has consequences as it is in excess of 40 degrees with lots of trees.
Personally, I like E chair off of peak 9, Whale's Tail and the upper part of peak 7, Horseshoe Bowl, and the hike off of Peak 6. There's the burn on Peak 10 that can be interesting, but given the other terrain, I rarely make it over there.
Of course, if you really want to find the goods, your best bet is to take a lesson. An instructor will help you find the terrain that's appropriate for your skills with the best snow conditions, Otherwise, you may be hunting around for quite a while and may never find it.