It's been 20 years (almost to the day) since I climbed McAdie. I went up from Arc Pass and traversed on to Discovery Pinnacle, Whitney, and Muir (in that order). I remember the climb up to Arc Pass to be nasty scree. The rock on McAdie was very enjoyable class three. It's been a long time, but I don't recall the need for any route-finding tricks. There seemed to be plenty of different ways to go.