|Elevation tracking from my Garmin 310x GPS|
I would recommend first-timers do the north to south hike. We were rarely passed by hikers traveling south to north since most were traveling from the North. However, we did pass a couple of crazies who were doing the R2R2R in one day. Unbelievable.
Anyway, I liked the graph my Garmin recorded and thought, if you were thinking of going, you'd like it too.