We had such a good stay here last weekend. Firstly, the location is superb, right overlooking the river and within walking distance of everything - both The Guggenheim and, in the opposite direction, Ribera Market are within 15 minutes walk.
Marivi was a great host. She answered my questions promptly pre-booking, phoned me internationally a few days before we arrived to confirm check-in details, and then stayed in touch by WhatsApp before and after we arrived.
The apartment is roomy, with two bedrooms (one double, one twin), two bathrooms, and a futon in the living room. The kitchen was well equipped with most things you would need for a city-break. And Marivi kindly ensured that when we arrived there were plenty of basics such as milk, toilet roll, washing up/dishwasher utensils, etc.
I'm already planning for a return trip!