Jana's apartment is extremely nice and inviting, and Jana is doubly-so! The room was huge, with high ceilings and a ton of natural light. Everything was very cozy and comfortable. Great amenities, bathrooms, and bed. I was so glad to come back to it after spending all day hoofing it all over town.
On that note, it's a very, very convenient location for a newcomer — only blocks from the HAU, the Jewish Museum, Checkpoint Charlie (too touristy, but worth passing by), and several U lines. Its wedged between several awesome neighborhoods, so even just wandering around is fun. Very easy to travel all over, stop back for a short breather, and go back out again.
Unfortunately I was out and about so much that I did not get to hang out with Jana, but she is very kind and very interesting. I would absolutely consider staying with her again the next time I'm in Berlin (I hope it's soon!).