We really liked our stay at Fiona´s apartment as it was centrally located and the kitchen was well equiped.
I would recommend the flat for a couple of two and two single persons as only one of the rooms has a double bed which is big enough for two people. I know that this was mentioned in the description but for being honest I had no idea what "being of an old Scottish size" means.
The beds indeed were very cozy for the two couples travelling with us - at least the men were very happy that the bed was a little small ;-))
All in all we had a great time in Edingburgh and we liked our stay in the flat a lot.