As a Duo, you can leave a level or two early for the next camp. Case in point, last night a BLM67 invited me out to the Alzadaal Ruins on the QQ Poulter mobs, and exp was good for a duo (299-350 per kill), although chains were difficult due to pulls and distance between mobs.
I personally solo'd a fair amount of that guide (24-50). From 50-58ish, I did a lot of Campaign and main-healing parties. At 58, though, I started working with my wife's BLM of similar level and we've been duo'ing since (currently 66).
A SCH can follow that guide very well in most places, and we have the benefit of relying on "main heal onry" parties when necessary as well.
Edited, Jul 29th 2008 10:42am by Acturus