My two cruises consisted of a 4-nighter out of Miami, calling Nassau, Coco Cay and Key West, combined with the 3-nighter calling Nassau and Coco Cay. I'm 42 and had my own cabin for the 4-nighter (the single supplement was so small it may as well have not even been considered one).
For the 4-nighter I was with a friend, her sister and her two friends, all around 45-55. We chose this cruise because there were some in our group who could only be away for five days and this one had a great price. It never would've been my first choice to 1) cruise for less than seven nights or B) cruise to the Bahamas in Feb but I had no choice and I don't turn down the opportunity to cruise, regardless.
For the second cruise I was with my sister (49).
Cat K cabin - TINY. No closet shelves, no storage space.
Cat SO cabin - Small but fine for two people. Okay amount of storage. Our "partially obstructed view" was QUITE obstructed.