Quote Originally Posted by Purpleflavor View Post
There's no exp penalty for a group of 2, and speed runners have said that duoing is faster than soloing (with the right class combo). Duo questing is faster by a few days if you follow a speedrun guide like Joana's. The issue with duoing is scheduling playtime. Multiboxers do not have that problem.
The fastest to cap record is a solo mage AoE farming... Otherwise I think Hunters are one of the fastest solo and both a Hunter and Druid get extra movement speed from level 20 on (outdoors only on the Druid). A duo Hunter+Druid mainly questing outdoors should be pretty fast to cap.