We stayed in Olessia's flat for 3 nights, and cannot recommend it enough. Or her, for that matter. She was communicative, hugely helpful when one of us was in a pinch, and has created a space that is clean, inviting, and furnished with all the amenities one might need. She has also taken the time to create an entire dossier of things to do while in Edinburgh.
The flat's location is also very ideal; she's a close walk to Princes Street, and within walking distance to Old Edinburgh - but she's also removed enough to make one feel like a local.
We would happily stay in her flat again, and again, and again. Which may be likely, since we plan to come back to the spectacular city of Edinburgh!