Ivos was very quick to respond and even accommodated me an extra night since my flight was cancelled—
Check in was so so easy with Alec, and contrary to what you may presume, the apartment is not as noisy (when you close the windows anyway) as mentioned. You are afterall, in the middle of all the action next to Alexanderplatz. The view itself makes up for any noise that may or may not annoy you.
As for the flat itself—everything you need is there: cooking necessities, bath and shower gel, extra bed/couch, huge screen TV, balcony on the same floor in case you need a cigarette, and above all, spotlessly clean upon arrival. Would stay here again !