Actually, there are many reasons! Let's start with the fact that Alberto and Osmary went out of their way to make our stay there special. It was our anniversary the first day we arrived. Alberto and Osmary not only cooked up a special (delicious) dinner, complete with fresh fish, flaming cake and excellent cocktails, but they also brought in a classical guitar player to entertain us (and give us a few dancing lessons). In our room that night they had left champagne as well!
The layout of their house is lovely with lots of plants and sitting space. This was the best place to sip rum, smoke a cigar (our first) and meet other travelers. Alberto and Osmary speak English, but were so willing to suffer through our Spanish so that we could practice and were happy to answer so many of the questions we had about Cuba.
Another reason I want to mention: in town one day we got to talking with a Cuban woman from Trinidad. She mentioned that she had lived there all her life and that this couple (Osmary y Alberto) were often doing things that were good for the community (i.e. donating clothes or food) and you can see the ripple effects of your stay here as having a positive and sustainable impact on the town. We stayed here three nights (which is longer by 2 than any other place we stayed in Cuba). We wished to stay a fourth, but they were full, so we stayed with Alberto's mom in the middle of town, which was another fabulous casa. Amazing family, amazing casa! Vamos a regresar.