we stayed with my 4 years daughter there for 2 weeks, it was a pleasant stay the apartment was super clean and the location is very close to Galata Tower and the famous Taksim square and also to the sea view "golden horn".
Omer was very helpful and he answered our questions, we didn't meet him but check-in was easy and the apartment included everything we needed.
you should be aware that there is a close mosque (like everywhere in Istanbul) and the call for prayer will be early in the morning, but the sound was not a problem for our daughter, and depending on the season I recommend bringing something for mosquitoes.