We just got off a short cruise on the Miracle- we were in an aft balcony on deck 5.
While we did experience a bit of weather (rain) and some energetic seas (more movement than I usually feel), those did not bother us in the least. What DID bother us was at night when we were trying to sleep- we were moving very slowly (around 1.2 or 1.3 knots) the first three nights and there were maddening, intermittent "bumps" against what I presume was the hull. It shook the floor, and was magnified by (I presume) the bed/mattress set up. They either kept us awake, or woke us up many times throughout the night.
The only night we did not experience it was our last night coming back from Ensenada to Long Beach, when we were traveling quite a bit faster (around the 13 knots range).
I would happily book the Miracle again but will definitely steer clear of any of the aft balconies as I have no way to know how far "up" that shaking and shuddering can be felt. (I have been in an aft balcony before- different line and different ship- with no such effects).
Can anyone chime in with knowledge of how that feeling is affected by travel speed? Is it just as simple as "the waves are more easily felt when traveling slowly"?