I've got both, a 50 Plant/Martial dom and a 50 Plant/Dark troller. Even though there's an overlapping set, they play so much differently at end game. The dom plays more like a scrapper with some control, but the troller feels more like a tank with controls, buffs, and debuffs. The troller is just far more survivable, and feels like it contributes more to the team. So don't rule it out man!