We stayed in a room on the MK side of the WL with a door that opened onto the lobby. Personally, I thought it was the best room possible. We had a view of the castle, Wishes, Space Mountain on one side and were part of the beautiful lobby on the other.
As far as noise goes, I didn't find it bad at all. The mornings we were still in the room late enough, we could hear the noises from the Whispering Canyon Cafe. Since we were on the 6th floor, it seemed distant and somehow just part of the atmosphere.
If you like to sleep in and require absolute quiet, I guess it could be a problem.