My husband, daughter, and I stayed at this apartment for seven days in early January. This was not vacation but rather a combination of dropping off my daughter for a term at the university here as well as some work obligations.
The Pros:
Location: Outstanding location, as others have noted. If you want to sightsee along the Royal Mile, High Street is less than a minute's walk away. And perhaps a 5 - 7 minute walk to the central quad of the university.
Communication: During the booking process and prior to our visit, the host was extremely responsive--I had a reply to almost every query within a couple of hours.
Access: The host and housecleaner were extremely kind and accommodating in allowing us to drop off our luggage a few hours earlier than check-in so that we didn't have to drag it around with us the morning we arrived in the city. Also, while you must either climb or descend a hill to get to the apartment, you can do so without having to climb any stairs--very helpful, if you are carrying a lot of luggage (as we were) or if someone in your party has mobility issues.
Layout & furnishing: The apartment is on the small side, but well-laid out so that it doesn't feel at all cramped. The couches are comfortable. The TV is well-equipped with on-demand and streaming services. There is a desk which provides a nice work area. The kitchen is fully stocked with pots, pans, plates, glasses, mugs, cutlery and a variety of kitchen utensils--everything, including potholders, ready at hand.
Wifi: I saw an earlier review that indicated the wifi was somewhat slow, but this was not my experience, and I was on the internet *a lot* during the stay, since I was working while there. Downloads and uploads went smoothly. I don't think you'll have any problems.
The Cons
Cleanliness: The general apartment was reasonably clean; however, the shower curtain was black with mold at the bottom, with streaks of mold that ran up about waist high. Serious ick factor. Clearly this problem has been building for a while. I reported this (including texting pictures) the day after we arrived, and received a quick apology from the host, however no offer to replace it. Four days later, with only a day and change left in our stay, the host sent a message saying that he could bring a replacement that night.
Overall repair: The baseboard near the front door is missing, and the hole that is left is stuffed with steel wool. Throughout the apartment, there is chipped paint and scuff marks. The mattress pad in the bedroom nearest the front door is badly pilled, and the sheets so thin, that I was uncomfortable sleeping on it until I laid down a wide, thick scarf I had brought with me and slept on that. In general, the apartment has the feel of a place that used to be really nice but that has been somewhat neglected. Probably not a problem for most people who are staying here as sight-seers, since they're probably not in the apartment much. I spent more time in the apartment and so noticed these things.
Noise?: I'm not sure if this will be a con for you--it didn't bother us that much, but then we live in an apartment in a busy city, so we are used to city noises. But in case you are noise-sensitive: the walls of the apartment are thin. While we were there, the noise from the close (alley) outside was intermittent until about midnight during the week, and until 2a on the weekend. This is generally just people walking past and talking as they go, so the noise doesn't linger. You'll also hear any noise from the upstairs apartment.
Communication during the stay: We reported several issues while we were in the apartment (the moldy shower curtain; the badly pilled mattress pad; the missing second set of keys which the directions said would be in the apartment; the lack of plastic bag liners for the garbage cans; the trash that was left in the doorway (I'm guessing by the neighbors, but perhaps it was just passersby in the close). Each time, we received a quick "Sorry about that and thanks for reporting!" but no offer to rectify the situation. The moldy shower curtain (which was truly disgusting, as evidenced in the photos I shared) and the second set of keys (having only one set made it difficult for us to coordinate our three different schedules) were issues where a quick fix would have been especially appreciated. The host did send a message about a day and half before we were to leave offering to bring a set of second keys and a clean shower curtain to the apartment, but by that point, with only a day and a half left in our stay, we were so busy racing through our last obligations that we didn't get the message until after we had left.
Over all, I would say that the host was a very nice host, but not what I would think of as a "super host," as designated by airbnb. This is the first time in all my airbnb experiences where I probably would choose a different place to stay if I were to return to the city again.
Some Notes about Accessing the Apartment:
If you are coming by taxi, tell the cab driver to access the close via Cowgate rather than High Street. Coming in from Cowgate, the driver will be able to drive halfway up the close and let you off an easy 5 meters/15 feet from the front door of the apartment. The upper half of the close (from the apartment up to High Street) is foot traffic only.
The semi-enclosed doorway (where the lockbox is) is almost pitch black, even in the middle of the day. There is an overhead light in the doorway, but it doesn't come on