The place is located in a real cool multicultural neighborhood. You are within walking distance to the most touristy parts (like Karakoy and Istiklal st.) and also most local-hip parts of Istanbul (such as Cihangir area).
For arrival, if you come to Taksim Sq. by metro you can walk to the house and the directions posted on the page are fabulous. I didn't even have internet (data) on my phone while in Turkey and I never needed to double-check anything with the host in order to get where or what I needed. The corner store (literally at the corner of Sardar ElIkram) has the essentials you might need for a fair price. The neighbour cats are cute, a Russian blue had a 2month litter of 3 and the 2 others a calico and a black cat (who mostly was seen on the neighbour's roof and I suspect was the father of the litter) were friendly and precious as well. Oh yes! Istanbul is a city of cats so get ready to meet all kind of characters and have this lovely glance from the residents who love to see visitors respecting the cats.
There is only two things you need to realize when visiting Istanbul; one is that some regions are extremely uphill-downhill. This includes the location of Le Petite House. The other is that even though the house is tiny, my husband who is almost 2 meters tall and I were able to get around and spent our time there fine. But if you are two bigger persons you might want to consider checking Arjen's other listing which is more spacious. Also, narrow stairs (just like uphill streets in Istanbul) are a norm in the city's apartments. To have a better stay, literally ask you knees if they are ok with these conditions. It was no concern for us anyways! We had fun.