I highly recommend Emilio's place in Beyoglu. We were two adults and two teenagers and the place accommodated our needs perfectly. Bedrooms were comfortable (the one with the bunk beds is small but serves the purpose just fine), the kitchen was outfitted well and the living and dining rooms offered plenty of space to lounge. The decor and finishes added a great feeling to the place.
The location was perfect for us. It is only a few minutes walk to Galata Tower and the surrounding restaurants, which there are plenty to choose from. It is also an easy walk to the Galata Bridge, which leads to the spice market and all of the other sites across the river.
Emilio was great, making sure we had all that we needed during our stay. I would happily stay here again.