My expectation is that Reaper will be akin to Samurai, but like Dragoon.

While Monk and Samurai are both speedsters with their GCDs, Dragoon has a slower GCD and hits like a truck to compensate.

I believe that Reaper will be slow like Dragoon, but will have extremely powerful GCDs to make it a selfish DPS like Samurai, Machinist and Black Mage.