Bernas place was exactly as described. Check in was a snap with very, detailed idiot proof instructions! The communication was excellent right from the time of booking and until we left. We always received a response within minutes no matter what time of the day we contacted her.
The place is quite cosy for 2 people with small shops to buy fruits, bread, eggs and other daily use items all around the apartment. Taksim square and metro station are just a 6-7 minute walk
The only point to note is that, as described in an earlier review, there is a steep road to walk up to reach Taksim. We are a pretty fit couple and we made the climb only once each day in the morning, so it was not much of a bother. But be aware that this is a steep climb and you are likely to need to catch your breath when you make it to the top. But if you do not plan to use public transport in Istanbul and are going to use taxis then this should not be a problem at all as taxis pass by the apartment all the time.