Everybody commented about the stairs, all 109 (or was it 110?) - it really takes your breath away but in itself, it is a great "adventure" - not recommended for people who have problems climbing stairs though. But it was a superbly nice apartment and clean.
Lisa was kind enough to let us checked in slightly earlier and it was highly appreciated.
The apartment itself is right "behind" Radisson off the Royal Mile, really no complaints on the location - it is smack right in the middle of road linking the both castles, excellent.
Everywhere is walkable though I would suggest to buy a day ticket for bus, for some places that you just need rest your feet - it is after all, a "hilly" city.