My mate and I stayed at Aydins apartment and had a great time.
This is Aydins home and feels very lived in, draws, fridges and cupboards are full of his stuff, we were absolutely fine with that but some people might want to bear this in mind before booking.
Aydin gave me his number and we chatted over whatsapp where he was very quick to respond to any questions.
The house was tidy and clean enough, two separate bedrooms and a living area mean that it is great value for money.
There is no aircon which made sleeping a bit hot in the Istanbul summer, I imagine its fine at all other times though.
The apartment is just a couple minutes walk to the main Besiktas bar area which is great for either a quiet drink or a lively evening in a live music bar. It's also fairly close to landmarks such as The Hagia Sofia museum, Blue Mosque or Taksim square, both are a relatively short tram trip or cheap taxi trip away.
I'd recommend this place to friends visiting Istanbul that want a nice homely no thrills space where they can relax and sleep before spending a day out in the town.
We also did the Bosphrous boat tour from Karakoy pier which is about a 15 minute walk away, this is also where the train is. We did the hop on hop off Bosphrous tour and I would highly recommend it.