Bring back crowd control.
Sure.
Bring back branching dungeons.
No. Tedious dungeons with numerous paths are not exciting. They are tedious. They needlessly draw things out while adding little. I used to play WoW, way back in the day. Dungeons like Wailing Caverns, BRD, BRS, and Razorfen Downs were abysmal. They were not fun. They actively pushed me *away* from running dungeons. I despised them then, and I despise them now. The dungeons in ARR weren't/aren't as bad as those in WoW, but they're still a bit tedious. The only reason I run them is for leveling roulette, or maybe to help someone else out. I'm not married. I don't have kids to neglect. I just don't like them.
Bring back ADVENTURE.
What? You do realize that within a week people will have plotted out the 'optimal' route, right? And then all those little side-paths will just sit unused by everyone except newbies. Not much ADVENTURE there. Not much ADVENTURE in being stuck in an hour long dungeon, either, for that matter.