Clemens’ apartment is the perfect home base for your stay in Vienna! He is located less than 5 mins from the subway on U1 and there are are so many food options within walking distance (try Mochi Raman Bar!!). You are 4 stops from Stephansplatz for the core of the Old Town or 1 stop from Praterstern.
His apartment is perfectly outfitted with everything you need for your stay. It’s small but perfect for a couple or a solo traveler. There is no street noise as you are facing inwards, but the other tenants can be loud at times. Should not deter you whatsoever!