Great location in Edinburgh and very nice apartment with all necessary features. You can reach very easy the heart of the city via bus cab or wolking. To the castle it's less than 10 pounds for a cab.
The street is very quite and you can easy find a parking if you have a car (it is expensive during working days 1 pound per hour, but free during the week end). In the near by you can find some shops for food.
I think just a little improvement on the instruction for the house and advise about the neighbors: probably the walls are pretty thin and the neighbors can be easily disturbed by the noise you can do.