I did Pride in 2005 (Feb). Ship is very nice. It is by far the best class of any Carnival ship. It has fewer passengers so there was never any real crowds (even thought it was sold out). The decor is interesting. It is all replica of Renaissance Art. This means the decor may be a bit "intimidating" to some (you'll see). However I had a great time. Did the Tequila distillery tour in Puerto Vallarta, hired a driver in Mazatlan ($25 each for 6 of us) who gave us a great tour and took us to a great place on the beach for lunch. In Cabo it rained but we did the whale watching tour. I really liked it but it was cold and rainy (free beer and margaritas helped). Since it was such a bad day we went back to the ship and relaxed.
Not sure of the whale situation in March, but I was lounging by a big window on the promenade deck and saw a number of whales broaching. It was really neat.
All in all the trip was great. I tend to like the Caribbean side of Mexico better (weather is nicer) but the Pride is a great ship and we had a great time.