Wonderful location direct in the center of the Royal mile and close to the train station and airport bus stop - 5 minutes walk from both. There's more than 90 steps to climb to the penthouse, so you'll get some free exercise - this does get a little tiring after a while. The views of Cockburn street and over New Town are nice, with the Firth of Forth visible in the distance. On clear days you can even see the Forth bridges.
The aparment looked a little dated, but it's a lovely old building, so no complaints there. Communication was great.