I would give Sean a 6-star review. His place is fabulously located about 15 minutes walk from Waverly, i.e. 20 mins from the Royal Mile. Spotless clean, comfortable and nicely decorated.
Sean was a great host: really clear communication throughout our stay, easy to reach and approachable.
His will be the first place I would look to stay on my next visit to Edinburgh.
Word of caution: the flat is on the third floor, you will need to climb 63 steps (I counted).