We stayed in Yana's flat last weekend while visiting some friends in the city. Yana was really helpful and easy to contact throughout our booking and we were able to arrive very late on the Friday night. The flat is really spacious, and could easily accommodate our family of 4 (two young children, cot helpfully provided) plus 2 other friends. Very clean and comfortable. Everything worked, except the main shower (which Yana had told us about) and the alternative shower was perfectly adequate. It is in a very central location, no problem getting into the centre of town on foot or short bus journey. There is a useful Margiottas (corner shop/deli) round the corner.
The only negatives are ubiquitous to Edinburgh really - parking is free at the weekend but tricky to find a space, especially if you arrive very late on a Friday! We parked about a 5 minute walk away and got much closer on sat morning. The flat is, as stated, at the top of a tenement block, they do not have lifts. Oh and it seems you can't actually get onto the canal towpath from the bridge, even though you can see the canal, which is mildly annoying.
All in all, we had a lovely weekend and would certainly recommend and would plan to stay again.