Our stay was beautiful and our hosts helpful, kind, and responsive. You can't beat the view and location. We absolutely loved it. As others have mentioned, there's a lot of hill and stair walking that has to be done. Many of the driver's won't come all the way up the hill, as we found out when we checked out and had to drag our 4,000 tons of luggage done 65 stairs, down a massive hill, and back up another one because the taxi wouldn't come closer. There is no elevator/lift.
The windows are single pane and are not at all sound proof. So, if you're noise sensitive, bring some plugs. The building and flat are very old and it does show it's age a bit, but that doesn't impact the stay quality. There is also a gorgeous private area out back that makes it feel like you're in multimillion bit of Edinburgh.
We'd be more than thrilled to stay again. A hearty thank you to all our lovely hosts. :)