We're Midwesterners and this was our big 25th anniversary getaway. We chose this cruise based on the itinerary, and researched the ship as a secondary issue.
My only MAJOR Disappointment with this cruise was that it ended. We loved the ship, and especially loved Barcelona as a home port.
My main minor disappointment was the quality of the "basic" coffee on the ship not being up to my home standards. We also experienced one "glitch" with the ship that was inconvenient, and took almost two days to resolve—a malfunctioning phone in our room. This prevented us from getting a wakeup call on an excursion morning, prevented friends from contacting us, and also prevented room service from contacting us prior to bringing breakfast. NCL's staff was reasonably responsive, even lending out a spare portable phone, but we had some anxious moments because of it.
Midship balcony--OK for two, but would be a challenge to squeeze in more. With lack of midship elevators, some might find it a long walk to get places, but we didn't mind.