Fantastic choice! The apartment is very cosy and was a perfect stay for our group of four. We loved that it was so fully equipped, literally anything you would need in a kitchen is there, there were also great ipod speakers, a hair dryer, and guidebooks. The wireless works well.
Marion is such a sweet host, she welcomed us and was very responsive before and throughout the trip, she also offered to post back a leftover item we had forgotten! On top of this she had put in some groceries for us in the fridge upon arrival and the cupboard is stacked with pasta, rice, sauces, all types of seasoning which we were free to use. The beds are very comfy, everyone got 2 pillows each.
Location is great, its within walking distance to basically all the main attractions to cover in the city which was so convenient.
The apartment is on the third floor and it's worth noting you need to go up stairs for this, nothing too tiring though. The entrance and stairs seems a little dark and old but this doesn't reflect the apartment itself at all. We would definitely recommend this apartment, its a fantastic deal and a very comfortable place to stay in Edinburgh.