Everything you have read about the San Diego to Ensenada transfer on Cruise Critic is true, but probably understated. It was the main topic of conversation at the Cruise Critic RollCall get-together, when the cruise director asked for comments or questions.
Try to imagine being in a giant warehouse with 2,000 other people, with one set of bathrooms, no signs telling people where to check in, no public address system to inform passengers of procedures or bus departures. There were free shuttles to Balboa Park, in an attempt to placate passengers who were stuck there for hours. When the buses were ready to depart, port employees were literally screaming out bus numbers to passengers who, for the most part, were talking among themselves and not paying attention or were outside sitting by the water. Once you got to the buses, nobody checked numbers, so the number system is basically meaningless. My advice is just get on a bus as soon as you can and get the hell out of there. That's what we did (we used our Celebrity Select status to get an earlier departure). The trip to Ensenada is just under 2 hours. Then we waited in a line of buses to get to the ship. There went another hour, as we sat in the bus, within sight of the ship, but unable to get to it. One of those "so close, yet so far" situations. Since we had flown in that day from the East Coast, our day started at 4:30am when we got up, and we got on the ship at 8:30pm. The word "grueling" doesn't quite capture it.
The cruise was fine. Five days at sea were relaxing and a very gracious way to travel to Hawaii. We enjoyed all the ports, although Maui was moderately stressful, since passengers have to go through US customs (not a big deal) and it is a tender port. They only allowed TWO tenders at a time to make the trip, so you can imagine what it was like trying to get all the people ashore who wanted to go. Returning to the ship was much better.
Our cabin was a standard balcony cabin, Deck 8 aft, port side. Cabins on both sides, above and below. The size was perfectly adequate for our needs. There was plenty of storage, especially in the bathroom. Shower had a shower curtain. The location was excellent, and convenient to restaurants and elevators.