Gayfield Place is an excellent base from which to explore Edinburgh. We stayed during the Fringe Festival and were able to walk to all venues. And it's only a 15 minute walk to Waverley Station, plus easy walk to several pubs, restaurants, shops and supermarket.
The apartments 3 large bedrooms are great and beds very comfortable, fantastic kitchen with everything you need and lovely big windows looking out to a quiet courtyard garden with large trees. Tram works are still going on, so parking may be a small challenge to begin with - however if you don't have to take a car, don't. You really won't need it. Highly recommended.