The location, Royal Mile, was the saving grace. The Igloo door entrance system lost us a couple of hours, and the owner (resident in the Middle East) was unobtainable. We were fortunate enough to meet a telecoms engineer in the Tolbooth Tavern, who came to the door and confirmed that the app key / code we'd been given was out-of-date. Very stressful.
The apartment was reasonably clean, except for the WC which smelled of stale urine.
The owner wrote, without any apology, basically saying that she had bad experience with tenants (i.e. it is our fault), but did not return our call (we needed help to get in - eventually managing through her sister, an emergency number, but the app code did not work all week, so we had to share a key from a small black keybox, and with only one key to the outside door at street level (making it difficult to go out separately, especially since the intercom was smashed - we reported this but that elicited no comment either. We would not recommend this property (although the location is excellent).