We went for the fringe festival and gosh, what a location! Almost don't want to give it a good review so we're able to get in again next year! The flat looks out onto the Royal Mile with every room in the flat having a fab view of the street performers and general hub-bub. As other reviewers said it did mean it was a little noisy at night with the street cleaners/bins that are collected every day during the festival but that was to be expected and nothing some earplugs couldn't sort.
I'm a very fussy sleeper and I have to say the mattresses were excellent. Lounge area much nicer and bigger then we thought. Rooms were all nice. The only downside is the one room has two double beds which might be a little bit odd if there are 3 couples going.
Overall fantastic. Would certainly stay again - whole process very easy. Plus Kaddeer was kind enough to sort somewhere we could leave our bags.