I feel like Gunbreaker plays a bit more like a Rune Fencer than than a gunblade user, but that's because I really don't like the class animations and sounds. I wanted it to be more of a two handed weapon than the current one-hand implementation. All that aside, all of the tanks have VERY simplified damage rotations and mechanics in 5.0, so if you are looking for something more complex, then you'll have to swap to DPS.

It feels to me like the reason for all of the simplification was to lower the skill floor for tanking, which they have done quite well; however, they also drastically lowered the skill ceiling, which is why tanking feels a little underwhelming to me.