I stayed with my family recently and loved it.
Great view of Edinburgh and right in the heart of Old Town. Quick walks to pubs, bars, restaurants, and other night life. The Royal Mile and Edinburgh Castle within short walking distance as well. Easy movement in and out of the city. We had to drive but would recommend taking a train to Waverly and taking a cab or walking to the flat. The flat is on the top floor so be aware if you require assistance. Flat is nice, spacious, and clean. It has plenty of dishes, utensils, and other items for cooking or eating. Small table with chairs for dining and a large couch for lounging. Great place for 3-4 people to make base camp and explore the city.