The itinerary from Malaga to Lisbon, Portugal appealed to me and my sister. Additionally, we hadn't cruised on a small ship before.
The best things were the informality of it, the personal attention of crew, and the lively interactions with other cruisers, and of course, Spain and Portugal!
Things work differently when there are less than fifty passengers on a cruise. When a port change was necessary due to weather, the captain gathered us in the lounge and explained wave height, etc. From our last port (in the Algarve) we were bussed a few hours into Lisbon instead of enduring a gruelling overnight trip around the coast. I am not sure that I would want to cruise out into the Atlantic on a ship that size. I didn't have any trouble with seasickness on the other legs of the journey, but I could feel the rocking.