Clean apartment with all amenities I needed for a week's stay. With the current check-in process (for which you will have to keep an eye on your e-mails) you can check in without any time pressure, and due to the apartment's location it's easy to get supplies, as there are a BIPA and Billa right around the corner and it's a 5-minute walk to Vienna Donauzentrum.
When you have issues or questions they are quickly resolved with a phone call.