Myself and my partner booked to stay in this flat for three days at the end of February / beginning of March.
The flat is exactly as described - a view of the (very melodramatic!) castle from every window, spotlessly clean and comfortable (loved the bed especially, very snug!). The flat was well fitted out with everything you'd need (and more).
It's very close to the Grassmarket with all its pubs, restaurants and such - a 2 minute walk. It's also convenient for lots of the other attractions Edinburgh has to offer as well, about a 10 minute walk to the Royal Mile.
Whilst we were there, the "Beast from the East" snow storm hit the East Coast, including Edinburgh - and all trains to England were cancelled as the train lines were blocked by snow. Fortunately, we could stay in the flat until we finally managed to get the train down to England - Lynne was really helpful in helping us extend our stay, yet another example of how hospitable she is. Our 3 day stay ended up being a 6 day one!