Ivan is a wonderful host: considerate, helpful, and super quick to respond to queries. He made restaurant bookings for me, and provided an extra mattress for my guest. The bed, incidentally, is large enough for two people, but I'd say only if you're on fairly intimate terms with your fellow traveller. Otherwise, ask Ivan for the extra mattress! The flat is very well equipped, smallish and yet spacious-feeling; it is lovely and warm in winter. Since there's no air-conditioning, I don't know what it would be like in summer, but since it's on the ground floor (another plus!) of a very solid old block, I suspect it will be nice and cool. The location is perfect: just far enough from the centre to be very quiet, yet close enough to walk if you're fit. The flat is, in any case, a couple of minutes away from the very useful U4 U-bahn stop, and, in the other direction, from the equally well-connected D-tram -- which runs straight from and to the main station, with stops all along the Ring. A tip: if you need to leave luggage before and after check-in and check-out, there a very handy Nanny-Bags facility just around the corner, in Hahngasse. They charge 7 euros for the day, and, since it's an unmanned facility, it's available 24/7. (They send you a code by text and email to open the locks) All in all, I can recommend this place (and host!) very warmly.