This was almost a shockingly amazing experience! Perhaps I feel so due to personal reasons for my travel, but I must say that Henning's place most definitely enhanced my stay in Berlin by far! So much so that I hated leaving the flat in the morning and coming back tired at night. I really wanted to spend more time in it. It is minimally furnished, just like I needed it, but done so with taste and lots of space - very important, but usually rare, especially in older buildings like this one. At first I wasn't so crazy about the all white walls with nothing on them, but when I realized that the biggest one is used to screen movies (there's a projector with a convenient HDMI cable in the living room!) I was sold on the spot! Add to it the spacious leather couch and a decent library of books in German and English (minus the Kissinger + Ayn Rand ones...sorry can't stand these two!), and all you need is an appropriate drink and company.

Finally, the location.
I thought I had researched the location well, but I was really perplexed to find EVERYTHING around the corner! The world's oldest (and still functioning punk club), ALL kinds of world cuisines at really decent prices, close proximity to other more gentrified (if you're into it) parts of town in 10-20-30 minutes walk or in no time using the many buses and 2 metro stations nearby.

Really, this is an EXCELLENT place in an even more excellent location. Henning was also great with his reliable, timely communication.
Airbnb has lately become a little bit of an industry for real estate agencies and businessmen operating their listings like hotels, which essentially undermines the whole purpose of the site. This is NOT one of those listings. Book it!