Rage spec is not overpowered. Most teams on Pot5 only run 1-2 rage spec for ranked. Rage spec destroys some teams in non-ranked WZs, but 1 marksman sniper can shut out a rage spec player easily.
Lets be fair here: there are 14 DPS specs in the game- 18 if you count the right trees as two specs. The fact that 1 of those specs is represented with 1 or 2 players in almost every ranked comp probably suggests that it's a little OP.