Lynne`s apartment is absolutely great (as she also is), we could not choose better. To start, it is just amazing to wake up with the castle just behind your bed. The apt is clean, spacious and have everything you may need from TV, Wi-fi and a very comfortable bed to kitchen utensils and an amazing spa bath tube.
You will be in the castle with less than 10 min walk. Grassmarket is just 2 min down the road and has lovely restaurants and pubs (I recommend Fiddle`s Arms and Beehive inn). In 15 min max you will be in the Royal Mile and princess street is also a 10 min walk, which is even more pleasant if you go through the park. Lynne has a book with some nice recommendations of things to do and plenty of guide books that you should have a look. We had a really great time in Edinburgh and definitely would stay in Lynne`s place again if we are going back.