Awesome stay. no 5 star can come near this place. Place is better than it looks in pictures. we will stay here only everytime we come to Istanbul
You don't feel you are in basement at all. So do not worry about that.
Just be sure it is on a hill (which make the view special). 500 meters you have to walk up or down the hill to get to the place (when you are going to visit other places). But after 500 meters you will get tram. Taxi and uber comes at gate, so that is also very easy.