We had a very good 3-day stay in Edinburgh, also thanks to this very well located apartment. Super close to Haymarket and the Conference Center. Also in a relaxed walking distance to the rest of the city center.
The apartment is clean, nicely decorated and has everything you need (including shower amenities and soap, which was very helpful but is not always available in other places). Super fast communication with George, who is very supportive. Check-in, check-out, wifi - everything worked perfectly. As mentioned in other posts, the place is below street level, so it's a bit more exposed to by-passing pedestrians and some traffic noise - but regarding everything within the apartment, a big "merci" to George.