We didn't actually meet Mercedes but her sister Maria was on hand to let us in. Communication was easy and cheerful but people are busy, so don't expect instant responses. The apartment is small but well equipped and our host had left some refreshments as well as everything we could need. There is a supermarket very close by and local bakeries and tapas places around a few corners. Some family members found the walk to and from town hard work but there are plenty of buses.
The apartment is secure and comfortable and rather light and new.
Although there is a picture of a terrace on the profile, it is a public one on the rooftop, not a private one. The views are great, however, and a nice spot for an evening drink or breakfast.