We had a great stay in Vienna at Lona's apartment - it uses space well (one bedroom, plus other beds in the lounge are elevated with a desk and plenty of space to spread out your luggage underneath). The apartment is just a few minutes walk from the Metro station by the Naschmarkt, which is also just a few minutes from town (or you can walk). Lona also looked after our bags for us during the day so that we could pick them up on the way to our flight.