I started riding this season at 18/-15 and it's been surprisingly comfortable. Last week I switched back to 15/-12 and kept catching edges so I guess once you go 18/-15 it's going to be hard to go back, although I'm not complaining.
1.5 to two inches of fresh pow made for near-epic conditions at Camelback today. Just kidding. I went with 18/-12 and a centered, 24" stance today. It was the best configuration yet, 18 in the front feels perfect and three degrees less in the back seemed to take some stress off my big toe and knee. I'll try it on my rocker next week and see how it goes.