The flat is very well located, surrounded by many restaurants, bars and cafes. It's only a 10 min walk from the metro and tram so you can get anywhere easily. Arek was also quick with his communication and also provided space for us to leave our luggage after checkout.
The only areas for improvement are that it's considerably more expensive than everything else in Istanbul and that the bathroom, while clean, was a little rough round the edges.
Would definitely recommend the accommodation and the city!