This is a tough review because there are problems with the property, but the owner is actually a nice person and tries to help. Unfortunately, our issues could still not be addressed.
We were unexpectedly stuck in Istanbul and needed a place where I could work while my kids could sleep, so separation on two floors worked perfectly for us. The unit is about 10 min walk from Taksim square although the walk is uphill but it was certainly manageable for kids.
The unit doesn't get any sunlight. The windows face a large multistory building which is very close, so you're staring at a wall. This was unexpected because the listing states that "there is also a large garden" but actually there is no garden in the unit. Garden assumes plants, flowers, etc. and we selected this so our kids might be able to get out. There's actually a veranda-like space (but no sunlight).
The unit is in a shared building, there were certainly noise issues. One night between 11 PM and midnight a neighboring unit (or unit above us?) started vacuuming and cleaning which resulted in quite a bit of noise. We were already running into another issue so we didn't bring this up. We were able to manage through it.
The day we checked in, there was no shampoo, shower gel or microwave: all of which were in the listing. We informed the reception that night, but that didn't help and we couldn't heat food etc. The next day I messaged the host and he hurriedly got us all of the stuff. He was genuinely trying to be helpful.
Then another issue was the AC. This building is in a shared space with a central air conditioning system. That AC would shut off from time to time. One night, I woke up three times just to turn on the AC because it was hot. The host asked me to inform the building manager. Neither the host nor the building manager knew English so they were unable to really understand the issue. The manager kept telling me that I don't understand the AC system. The AC shuts off (not just trip) when the room temperature matches the AC. He said do not touch it because it will turn on again.
But my experience (over more than one night) was that AC wouldn't turn on. The manager wouldn't believe me and he pretty much told me that I just "think" that it's hot because AC is not running. I gave up after that. Then to fix it, they tried to change the temperature from central system to 18C (we like it at 24C) a few times. I would readjust to 24C and it would go back to 18C. So I thought it's best not to tell them anymore. I think more than the experience, it was the experience that was demoralizing.
The host did arrange for a friend or an acquaintance of his, who knew English well, to talk to me and I explained it to him. I think he was trying to understand/help with the issue but things were not really in the host's control anymore.
Luckily for us, there was another independent AC unit in upstairs bedroom which continued to operate so at least our kids were fine. The central AC vent in the lower floor is in the main hall so if you have to shut off the lower bedroom door (like I had to sometimes for noise management) then the room can get a bit warm.
Overall, given the circumstances, we think our stay was "ok" but if we could, we would definitely look for another place first due to issues I mentioned. Having said that, the property did meet our minimum requirement where I could work and kids could sleep, i.e. the floor plan worked well for us.