Alfonso's house is largely as described in its Airbnb description.
My friend and I stayed in his two-bed studio unit, situated near the back of his rental building. The unit was clean, spacious, with a nice sized kitchenette and adequate sized bathroom. The kitchen and bathroom appliances were relatively modern and in good working condition. I was also delighted to find that Alfonso had cleaners tidy our room - including change our sheets - about every two days.
As advertised, Alfonso's building is situated next door to Playa Central and just a five minute walk from Baja Joes, two popular kitesurfing hangouts in La Ventana. And his building, while sandwiched between two other houses/complexes, is protected by a high wall on all sides, which is nice for privacy and security.
Alfonso himself is extremely responsive! His replies to my email questions would come within minutes of my sending them.
Two areas to which I might bring future guests' attention.
----For the duration of my four night stay, the shower water was some variation of cold-to-lukewarm. If you're comfortable with cold-ish showers, this shouldn't be a problem. But if you're like me, and want a good hot shower after getting off the water, this will be an irritation.
----I found the internet all over La Ventana to be sub-par, and the same was true of my internet experience at Alfonso's building. However, whereas the internet at other La Ventana establishments would be merely slow to load, there were sometimes hours of non-responsiveness with the internet at Alfonso's building. This situation did seem to improve after Alfonso had a technician reset the modem (perhaps to clear the cache).
Overall, I would recommend Alfonso's building. It's affordable, clean, and conveniently located, and I have no doubt that Alfonso - diligent as he is - will continue to work on improving the hot water situation and internet.