We stayed in this room at Dundar's place for just 2 days. Though short, it was absolutely wonderful.
Dundar is really helpful and if you're short of time in Istanbul I suggest you listen to his recommendations. Food to get, places to go etc... We loved his recommendations.
The room is very neat and comfortable. It was cosy and spacious. Although there were other guests sharing the house, we had absolutely no trouble using any of the utilities. The entire place is exactly as in the pictures and you'll definitely notice his creative side all around the house.
The only con I can think of is the steep road leading to this place. But my partner and I saw it as a nice way to get some exercise. So this definitely shouldn't stop you from booking this place.
Give this place a shot if you're definitely looking to stay near Taksim or the surrounding areas.