Our stay at Danni and Roland's place was spectacular! It's all the little things that made our stay in Edinburgh so spectacular, from finding the fridge stocked with milk and treats on our arrival, to the beautiful apartment in a wonderful location. We followed their suggestions for dining and a private walking / photo tour and all were great! In particular, espically if you find yourself in Edinburgh on a Wednesday evening be sure to make reservations for Divino Enoteca for wonderful food and romantic live music.
The only comment suggestion I would have for prospective travelers would be to travel light. We only travel with carry on luggage and no checked baggage (there is a washer and dryer available) so walking up 5 flights of stairs wasn't at all a problem for us, however if you tend to travel with a steamer trunk for luggage, leave it at home so you don't have to lug it up to the 4th floor.
All in all I wouldn't change a thing. In fact we have stayed in some nice places, but none nicer, more comfortable or better located than Danni & Roland's