We were travelling Cuba for 2 weeks. This was one of the best Casa Particolares that we were at. Note that all the Casa's we chose were based on reviews from Tripadvisor and Lonely Planet. So, the competition is respectable.
The 3 things that comes to mind:
1. The person running it (Alberto) was an angel when he went out of his way to help bus-courier our car rental contract that we left behind.
2. The house chef was like a five-star hotel chef. He made great meals, whatever you wanted and they were decoratively presented.
3. The hammock on the balcony