Klaus is an amazing, respectful and very thoughtful host. I would stay at his place anytime!
The neighborhood is super safe.
One huge surprise was the bike shop just a few block on Frankfurter Allee (on the way to Mitte). I was able to rent a bike for 10€ a day!!!
I absolutely loved riding everywhere in a German iron horse. It’s a safe and easy way to get around - I highly recommend it.
Also, Klaus’ place is surrounded by much commerce.
Berlin rocks for any solo traveler!