If you are looking to visit Edinburgh, there isn't a better place to stay. You are right in the middle of the Royal Mile and within walking distance to many of Edinburgh's sights and attractions. There are many places to eat, drink, and shop nearby which definitely heighten the experience.
There are great amenities in the flat which are invaluable, especially if you plan to stay longer than a few days.
Finally, you are given plenty of information about great attractions within Edinburgh if you arent familiar with what to do in the city.
I highly recommend stating here and will book again when I come back.