It was great! Maureen was a very good host: she gave us detailed information on how to receive the keys for check-in, organized a place where we could leave our luggage between arrival and check-in, and answered our questions during the stay within an hour.
The apartment is spacious and there is everything, you need: toaster, hairdryer and more (only the cutlery could maybe consist of a little more pieces). And last but not least the apartment is perfectly situated in the Old Town: the castle is in front of the window, the royal mile within 5min, and there's a lot of cafés and bars right in front of the door (I find it somewhat hard to find good coffee in Edinburgh. If you're like me: try "Café Jaques" across the street. The coffee there is good).
We were very happy with this apartment!