We had a wonderful stay at Martin's place. The host met us at the door and gave a thorough explanation of the facilities and the area. The apartment itself is perfect for a couple on a city break. It's clean and bright, everything works perfectly, and is fully stocked with all the necessities.
Location is wonderful - entrance is located in a tiny alley, so it's totally quiet. There was some light renovation going on in the alley, but nothing that disturbed us. The Grassmarket area is literally right up the steps, from there it takes only minutes to reach other parts of central Edinburgh. We walked everywhere. There is a well stocked grocery store up the steps and to the right.
And did I mention there is a cat cafe right around the corner? A cat cafe!