I've played nearly all the Vegas poker rooms, and this one is top 3 easily.
The action is unparalleled. This is no Venetian, with its huge shark and nut-peddler population, nor is it Station Casinos, with its regs and timid short-stackers. This is nonstop action, even midday on a weekday. Even many sharks will throw action around here simply because that's the flavor of Aria.
I once put my name down for 1/3 NL with 30 people ahead of me, and was seated within 20 minutes.
Staff is courteous to the extreme. The friendliest room, with the possible exception of the Venetian.
The tournaments are also excellent. Great room.