I'm 5'9", A generous 250 pounds, 53, broke my hip in 5 places. I travel quite a bit. So I've rested my head on a Hotel pillow or two.
I love the mattres on the ships although the couch is a different mattress, but still good. With all of the different hotel rooms I've slept in, the couch is still in the top third. I've stayed in rooms where on the second and third night it's been painful sleeping on a particular mattress, others where you can even feel the coils in the mattress. This was not the case with the couch/mattress, I've sailed on two seven night cruises on the couch(Gave my 70's parents the bed).
If a person is 5'8" or taller staying in the upper bunk can be difficult because of height. I know how to get a person an extra 2-3 inches there, but you need couch info so I won't bore you.
I like feather pillows because of an allergic reaction(stuffy nose and sore neck). I always need extra pillows also for acid reflux.