First I think Diego and Pablo want people to feel welcome and go out of their way to be welcoming and accommodating. In general there are issues with the state of the apartment. The room was smaller than expected and the mattress is uncomfortable, but the real concern for me was the state of cleanliness. The walls in the room where you stay have significant amounts of grime. The bathroom tub is rusting out and i did not feel comfortable stepping into it. The sink in the bathroom is even worse and there was not useable hand soap (because of the cleanliness of that as well). You will need to be aware that if anyone else in the apartment is smoking the smoke will blow directly into your room from the window they call the balcony, which is really just an open window ten feet away from your door with a draft going straight through. There are also some noise concerns.
I think they really want to be great hosts. They were very nice and the apartment is in a cool location and certainly is a budget listing. All of that said, i probably would pick something else if doing it again. But I did fine and many others have too, you just should be aware of the issues before you book.