My sister and I stayed in Elvira's flat for 2 nights and were pleased with it. I didn't get a chance to meet Elvira, but she provided excellent directions and responded quickly to our emails and texts. The flat is very clean, modern and in a convenient location. We were able to walk almost everywhere and it's only a few blocks from Atocha Station and Reina Sofia Museum. The wifi signal is strong and there's a TV with lots of channels. The neighborhood has a lot of character and there are some great cafes, bars and restaurants nearby. The two of us were comfortable with the size of the flat, but it's probably a tight fit for 4 adults. That said, it can be done as long as you don't plan on spending too much time inside.