I definitely think dungeon design could be freshened up quite a bit, but you end up with a lot of negativity anytime something like that isn't made to be easily burned through in a matter of minutes, and it's never by the casual crowd. Anything other than Savage/Ultimate must be designed to be not only incredibly easy but also incredibly quick, otherwise people complain that they have to deal with it in the daily roulette and it takes away from their time to play savage/ultimates.