I can't say anything negative here ! Had an over 2 weeks stay at Zeyneps apartment. Its quite in the high end part of asian Istanbul, super nice comfy, clean and new, ideally for 1 person or a couple, in a very calm neighborhood. Just a few minutes away from vibrant Bagdad street, the Göztepe park and the beautiful coast line of Caddebostan, Kalamis, Fenerbache etc. where you can enjoy local beach-sea life, amazing sunsets, picnic with friends or do some sport activities.
As I had a bicycle during all my stay in Göztepe, I was flexible (+ avoided the famous Istanbul traffic) and could easily reach Bostanci for some early morning city escapes direction Princess islands, the alternative district of Moda for coffee or drinks or the Kadikoy boat terminal in order pass to the European side of Istanbul.
Loved also the artisan bakeries of Caddebostan, and you can find also delicious street food around Bagdad shopping street apart of cozy eateries and coffee shops.
Its a perfect spot to stay, not at all a touristic (especially in the autumn-winter season) or conservative area.
Zeynep is very kind and responsive, like 24/7. Very warm and professional.