We almost felt like home for 6 nights in this nice decorated apartment. The bed and the futon bed were comfortable to sleep in. We loved the kitchen, unfortunately we were always out every day so we didn't use it much.
On our day of arrival both introduced themselves to us. Carsten gave us a great tip for eating All-you-can-eat mussels at a nice bar/restaurant in the neighborhood.
On one day it was raining heavy, but we were lucky because they had a couple of umbrellas for us in the apartment.
The neighborhood and nearby streets have beautiful brownstone buildings and other old architecture. There are several Delis nearby to buy groceries and food, which we found great. The walking time to the A/C train took us around 10 minutes. We were walking a lot on our vacation, especially in Manhattan. Believe me, you get used to it. It's a big city.
We never felt unsafe on our way to the subway and back, even in the middle of the night. Though there are probably different parts of Brooklyn which you should better avoid as a simple tourist.

On our day of departure, we were running a little late to get to the airport. But thankfully Carsten was there to help us and he was calling a special cab for us to get there in time. Please don't make the same mistake, if you want to go to the airport by the AirTrain, arrange enough time. It's best to leave at least 3 hours before your flight.
We would likte to stay at Joni & Carsten again if we to travel to NYC in the future.