We cruise regularly with our children (12, 6) and were curious about Carnival having sailed on NCL and Disney exclusively. We chose this itinerary (Ensenada and Catalina) based on convenience and were aware that they weren't the most exciting of destinations. Hence, we weren't surprised to find that it is barely worthwhile disembarking at these locations.
We did one excursion (a Carnival booked one) which I will discuss later.
First of all-- we were impressed with the efficiency of embarkation. The early checkin at the Queen Mary made for a quick and painless entry to the ship and we found the staff on shore helpful, if unenthusiastic.