The apartment itself was good. Looks like in the photos, good quality, internet is actually 100mbit/s as stated, had everything we need and even some welcome snacks from Tuncer.
The only concern was neighbourhood, since we dont cook ourselves, and there is not enough restaurants and metro is 15 minutes on foot. You would love it if you want to live among Turkish locals, but we prefer more touristic place.
Some other minor things - bathroom doesn't lock and shower is hot only if you lower pressure a bit (but the pressure itself is good).
Overall, I would definately recommend this place if it is not you first time in Istanbul