We spent 5 nights at Karl and Lisa 's apartment and enjoyed our stay there, it is completely clean, bed is very soft with clean sheets, the location is very convenient,we toured the neighborhood and it is very nice and safe, super market is just one block away, and so is the subway station . We also thank Karl and Lisa for being so kind and understanding to us with the check-in and check-out. Our best wishes to them. We hope to stay at their apartment in our next visit to the beautiful city of Vienna.