We were a group of 5 (2 adults and 3 children) and stayed at Seda's apartment for 3 nights. We absolutely loved the location, nothing could beat it - right at the bottom of Galata Tower with many cafes, shops, gelato places, supermarkets in the vicinity it was very convenient to buy things and eat outside. Tram to cross Galata bridge is about 7 min away. It's also easy to walk to Karakoy and Taksim.
The apartment is in an old building but in a very good condition. The view from the terrace is fantastic with Galata tower at your arm's distance and the Bosphorus on the other side. There is an elevator in the building but we only used it once as the doors gave us hard time.
Seda is a wonderful hostess, communication with her was fast. When we needed more toiletries she was very quick to send them to us. Probably the only issue was that the A/C did not work, so hopefully Seda can fix it in short time.
I highly recommend Seda's place for a wonderful experience in the historical neighborhood of Istanbul.