First, Fiona is such a dear. She is very helpful and just a pleasant person. We couldn't have asked for a better host!
Second, the location of this flat is as good as it gets. On the corner of Victoria Street, a stone's throw from the Castle and the Royal Mile. Walking distance to so many Fringe venues. And, amid all that, it's quiet. (There is some construction going on right now (Aug 2019) nearby that causes some noise -- I think pile driving -- but it's not that bad)
All in all, if you want a central Edinburgh flat that's near all the Fringe activity, this is the place.