I have a 16 year old Maytag and it was/is noisy. However, I did add some insulation to the areas 57 listed and on the bottom, around the motor. I used some eggcrate foam I had lying around. It helped tremendously. Unfortunatley, it is still loud. Our kitchen and family room are one big open area and we still only start the dishwasher when we go out or go to bed. Now with yours being a newer unit, it is probably alot quieter than mine. But I can only speak from my experience and I don't think it would hurt to try and insulate some bare areas.
We also have an old Maytag, 20 years. It's ridiculously loud. I'm not sure if yours is the same, but ours is one of the belt driven ones (glasses go on the bottom rack, which is opposite to the design of 99% of other dishwashers and all direct drive Maytags). Due to wear in the pump and motor, it's probably even noisier than it was when new. It's been terrifically reliable. Besides a new water valve and hack repair to the detergent cup, NOTHING has been done to it.
I tried insulating the door better, but it didn't do very much. I don't know how tightly you insulated around the motor, but be careful. Dishwasher motors already have a lot to contend with as far as heat goes, they need good circulation. Otherwise everything here sounds good. Keep in mind though, a lot of the sound improvements over the years have been better motors and pumps.
Anyhow, in the interest of modernizing our kitchen, we are replacing all our appliances. The Maytag, rusting racks aside, would probably run for another 15 years easily (and loudly). I figured we would go with another Maytag. I know they aren't anything like the belt driven ones (and I know Maytag no longer exists, besides being a Whirlpool nameplate). But it has the top sound insulation package from Maytag. Still won't be down to Bosch, Asko or Miele levels, but compared to what we have now, it will be good.