While I don't play on controller, I actually found the transition from WAR -> MNK much more smooth than WAR -> DRG. DRG is basically an off GCD machine, more similar to DRK than anything. MNK, meanwhile, is very few oGCDs with a similar rotation to WAR (3 GCD per combo and stuff) just with a lot more positionals. The positionals kinda seem like they'll be overwhelming at first, but the flow just starts coming to you naturally after a bit of practice.

That said, DRG is a lot of fun, and if you enjoy that job better I wouldn't fault you for it. It might even be less hassle on controller, I'm not really sure.