Fantastic apartment price/location/space. The tram M13 and M2 are near, you can take it from "Alexander platz" via Gustav - Adolf Strabe (tarifbereich) is you want to take the Tram M13 but this is the longer way. My recommendation take the M2 stop AM Steinberg. You can also take a taxi from the airport if you are going late in order to avoid a nasty call from Paul. The rest is perfect, Barbara the housekeeping is fantastic, very nice and polite (she only speak German).
I highly recommend this apartment but not Paul.
Thanks,
De Felice family.