I've been to amad's apartment for 6 nights.. Room was clean, warm and confortable, bathroom was quite good and provided with towels and a phon.. Amad has been really kind and always answered my questions about The city or public transports..
There's a also a piano you can play during daytime and a can you can cuddle ;)
Just 40m away from The apartment there is a tram that goes to Alexanderplatz