I have booked my room via planetromeo and then direct by email. I usually don't stay in apartments or this kind of properties, but I was really amazed with owner friendly and nice approach. Keep in mind that this is 'gay only' property.
It is located approximately 3 minutes from Taksim Square and just few minutes walking distance from all gay attractions of Istanbul. Perfect location. If you need to park your car you can do that in front of the building (free of charge) or in the secured car park 100 m away. There is no lift in the building, but that shouldn't harm you.
I have booked single room. Room was spacious enough with wardrobe and safety deposit box. The only one thing I didn't like was door with milky glass. I don't mind it, but I just didn't like it. I really loved though all design of whole apartment. Really nice taste and it is kept in great condition. It is spotless clean (rooms, bathroom, kitchen and living room).
They offered B&B option and that was great choice. For a small extra you'll get absolutely stunning breakfast. I told them, that I wish to have be served like that in 5* hotels. Just have a look, it was regular serving they do for their guests.
Payment only by cash. Complimentary Wi-Fi access is provided.