Good:
The door man was very tentative, Kamil's responses were very quick and helpful, and we were met by the Customer Liaison, who was very helpful also. All around the service was great.
Good air-con, wifi and fridge
There was free water left for us in the fridge, which was nice
The pick up arrangement from the airport was very handy
The breakfast (which was included) was tasty

Bad:
Although breakfast was tasty, it was a 20 minute walk from the apartment, which was a bit annoying as it ends at 10.
The street, and the surrounding areas are a bit dodgy. I wouldn't recommend staying here if travelling alone.
The electricity went a few times in the building and we were told 'that just happens sometimes', which was inconvenient.

All in all, we had a great trip. Istanbul is an amazing city and the apartments were very good value, all considered.