I stayed at Gulfem's apartment for 10 days while I was in Istanbul for a work trip. It served my needs perfectly, was in a great location and I always felt safe and comfortable. The apartment had everything I needed, although to be fair, I didn't need to use the kitchen much. It was a little "lived in" (not just an empty, sterile space) but I liked that and felt very cozy. The shower and water pressure were great. And I loved having a washer/dryer, which worked very well. (The dials were in Turkish but I figured them out.) Gulfem was very kind and responsive during my stay.
With regards to noise, the garbage truck does come by very early in the mornings, and there is a mosque next door so the call to prayer starts early as well. The walls in the building are kind of thin, so I could hear the neighbours coming and going at times. However, if you're not a very light sleeper it shouldn't be an issue (and you'd be hard pressed to find an entirely quiet place in Istanbul anyway!).