This was our third cruise on the Spirit (5th overall). Why Spirit? Because it is inexpensive and has a good itinerary. Otherwise, the ship experience itself is just ok. We were in three cabins (Wife and I in balcony, In-laws in a second balcony, and grown daughter and friend in an inside). The price was so good, it made for a very affordable vacation.
THE SHIP. The ship is fine. All the of the public spaces are nice enough and a nice dining room. It has a fun water slide and mini-golf. Otherwise, there is nothing in particular to note. There is plenty of open deck space if you like to walk or jog.
CABINS. Inside cabins feel spacious. Balcony cabins are well laid out. On the negative, smoking is allowed on balconies and if you are a non-smoker this can be a big negative if you have smokers below or beside you (as happened on our second cruise). Not as clean as it should be but ok. Too many dirty room service dishes in the hallway.
FOOD. Notable decline over the last few years. Some was quite good, but many items were 'disappointing'. Afternoon Tea is disorganized (this is consistently the case). You feel like cattle. Buffet was fine. Lunch in the dining room is my favorite meal. It is quiet and the staff is in a good mood.
STAFF. I have noticed a decline in moral of the crew also, especially in the dining room since the last cruise in 2010.
ENTERTAINMENT. Listening to the cruise director on the speakers gets a little old after a couple of days. I don't need to hear about all the items on sale. I hate the shows in the main theatre. The comedians in the lounge are usually pretty good.
EMBARK/DISEMBARK. Moves slow, but not too bad. On and off ship at ports is also fine with some lines.
PORTS. (Ensenada, Cabo, Puerto Vallarta, Manzanillo). To me, that is as much the reason for the cruise as anything. The ports were changed a couple months before sailing. I think it was due to problems in Mazatlan. If you are from California, you know that Ensenada is nothing to get excited about. It isn't even the Mexican Riviera. Shopping isn't very good. Some like to party. I like to get out of town. We really enjoy the Winery Tour. I've been on it twice. The wine isn't very good, but it is a pleasant excursion at a good price. Cabo San Lucas is mostly beaches and party. At minimum, do the Glass Bottom Boat to Lovers and Divorce Beach. Puerto Vallarta we did the Tequila Tour and enjoyed it very much, even though I don't even particularly like Tequila. Manzanillo is more tropical. One of the day trips to the interior will give you a good view of the real Mexico.