I agree that the cabins on deck 11 have very small balconies. No space for even 1 chair. Unless you wanted the spa cabin with all its amenities, veranda cabins in lower decks with full balconies are much better. There will be no noise factor, but you may experience serious vibration. Good luck!
I was on deck 11 once and at different times of the day it sounded like someone was bowling next to my cabin. I actually called the front desk and they told me when they moved the chairs around in the Explorers Lounge it was a bit noisy. Just make sure you are not right adjacent tot he Lounge. The balconies were quite tiny.