I always enjoy the Mexican Riviera itinerary, and decided to do this on the new Discovery Princess ship. The Discovery Princess is the sixth and last of the Royal-class cruise ships operated by Princess (Royal, Regal, Majestic, Sky, and Enchanted being the other five). All six of these cruise ships are, for the most part, similar in design and layout.
First off, embarkation was excellent. I really like the San Pedro World Cruise Terminal (about 22 miles south of LAX). I was surprised that they started boarding the Elites BEFORE 11am; many folks were on board and already enjoying the ship before 12Noon. As promised, the cabins were available by 1pm with an all-ship announcement. Princess now does their mandatory muster drill via an in-cabin video that you must watch and then a check-in of your Medallion at your designated muster station (this lets Princess know that you know where your muster station is). You are then able to practice putting on your life jacket in the comfort of your cabin at your discretion.
I purposely picked an inside cabin - I don't need a balcony and just go up to Lido deck if I want to see the outside. All cabins come with the Princess Luxury Bed - very comfortable sleeping. The cabin is brightly lit and there is plenty of shelving as well as hangers for your clothes. Good water pressure for the shower; good combination shampoo/conditioner provided. It seems like Princess has now returned to the cabin-serviced-twice-daily process.
Puerto Vallarta is an excellent port. No tendering is needed; you just walk off the ship. The cruise terminal is across the street from Walmart/Sam's Club and a Galleria shopping mall. It is also right next to - 10-minute taxi ride - the Marina Vallarta, where there are restaurants and shops. Highly recommend.