Ahmed's place is great for 1 or 2 people. Great location, 2 blocks from Tophane station (T1 train) and 3 blocks from Sishane Metro station. The only inconvenience for some people maybe the steep street access. other than that, the studio is very cozy and safe. Even when surrounding streets don't look in really good condition they are safe. I came back home at 2am a couple of times and I didn't have any problem.
The area is very close to the popular Istiklal street and it has a lot of restaurants and shops around. Ahmet will answer any question and try to solve your problems asap. Recommended!