I've run the quest on both factions, and it does seem easier on the Alliance side even though the Horde version has more apple barrels. Is it shorter? Is there a better time bonus? Are the goblins wearing Dwarf masks a handicap? Or is it just perception?
I definitely think the Barker quests are easier on the Alliance side. The Ironforge course is in a complete circle without any backtracking and you can jump down the mountain a bit to cut the circuit short at the end. You have to backtrack a little in Orgrimmar and there is no shortcut to the Horde quest-givers.
What is your opinion? Is there an Alliance bias for the Brewfest quests or are the Horde just worse at motivating Rams?