My only complaint is that the turbo mode is fairly loud. To keep our place clean we end up setting it one speed lower and leaving it run. A great improvement would be the ability to set the max speed that auto will go to. Then we could use auto on a slower speed for noise and still have the unit slow down when higher speed not needed.
The same controls could still be used you would just set maximum speed you wanted it at then press auto instead of auto completely taking over.