We stayed at Mehmet's place for almost two months. It is a lovely flat, nicely decorated, but it does need some touch ups. This is our honest review, without malice, as we also advised Mehmet. To summarise:
Mehmet was very accommodating when it came to getting a second desk for us, he also ensured a smooth and quick check in.
He did call a plumber to check on our leaking shower, but a fix was not possible while we were in the flat.
Unfortunately some of our concerns were left unanswered, such as a broken projector, broken couch cover, broken blinds, and a broken toaster.
A few other bits we noted, there was a hole in the wall next to the air-conditioning unit, the duvet and pillows were quite old and falling apart, the bedsheets and duvet cover sets were clean, but also quite old and have seen a few guests. Same with the towels, they were clean, but really used, and we only had one bigger towel (all others were hand towels).
The kitchen utensils could also do with a refresh as we had only one proper knife but 4 vegetable peelers? Other bits and pieces were also a bit mismatched / random / not working.
The flat was very clean when we arrived so that was a plus, although I did clean the mold in the shower grouts.
The flat is placed in a really nice complex, very very safe, with great Internet and all shops and restaurants nearby. We also didn't mind taking a taxi when we wanted to go sightsee Istanbul. But we work 9-5 during the week and only go sightseeing on the weekends. If you are coming to Istanbul as a tourist, it might be a bit far.
So all in all, the flat was really lovely. Tough for the price we paid it could do with a bit of TLC (and to be 100% transparent Mehmet did give us £86 refund as we had to leave 12 days early due to a family emergency).
Hope this doesn't come across too negative, and by the time you stay here, all these little things will be fixed :)