We enjoyed our stay at Engin's place. The communication was easy. They'd just furnished the apartment and there were things missing; but they provided us whatever we asked for.
The apartment is almost as photos. Living room is smaller than the picture and I don't think 10 people fit the apartment, at most 6 or 7.
The location is great. Close to Taksim, istiklal, waterfront, metro and bus stations. The neighborhood is lively but also noisy, specially at nights; there is a night club close by which runs up to mornings, I guess! Also, the apartment is on the third floor ( you should go up two floors) with no elevator. Have that in mind if you have an elderly person with you or have heavy luggages .