We stayed for 10 nights. Beds are comfortable. Ample space in the apartment. Cannot say enough about the morning staff. I'd just got off 3 flights from New Zealand and they were very professional and friendly. They went out of their way for us at every opportunity.
PM staff weren't to the same standard which was a little disappointing. 2 bars of soap between 2 people for 10 days wasn't great, and the bed wasn't made properly unless I made it myself.
Aside from that, the location is awesome. Close to the Taksim shopping and dining strip. Heaps of security around to feel safe.