my husband and I are 50, we travelled with friends in their 40's and we all had similar opinions regarding the Westerdam. I have travelled with Carnival, Celebrity, Royal Caribbean, and now Holland America. The Westerdam unfortunately was the worst experience out of all my cruise trips. The food was horrible in the dining room as well as at the buffet. The service was very poor accept at the bar and private restaurant. The drink packages offered were very inferior compared to the other lines. The entertainment was limited day and night and geared towards ages 65-80 and quite often shut down early in the evening.
The shopping on board was very poor and we experienced negative attitudes as if we were bothering them to buy something on several occasions. The LACK of music on a caribbean bound cruise was very surprising especially while relaxing around the pool area.
The suite we stayed in was roomy and the balcony was nice. The four excursions of boat/snorkle, jet skis, rhino riders, and zip lines were fabulous and highly recommended.
With all said, i would recommend Royal Caribbean cruise lines out of all ships for ages 40-60. It allows adult activities, great food, age appropriate excursions of all levels, great packages and amazing service and rooms.