This apartment is in an excellent location, near Checkpoint Charlie, metro and all kinds of shop. Axel is a wonderful host and he was very helpful with the local tips and suggestions.
Do note that this apartment is small and is meant for 2 adults and 2 small kids at the best, certainly very tight for 4 adults. Not much space for luggage and wifi is bit slow. If you don't mind close quarters then this is a good place to stay.