Last week I was part of the expedition by KDE (together with Kenny and Petra) to visit the local team that is helping us organize Akademy 2018 in Vienna.
I can say that I'm very happy :)
The accommodation that we're probably going to recommend is 15 minutes away by train from the airport, 20 minutes on foot from the Venue (10 on metro) so kind of convenient.
The Venue is modern and centrally located in Vienna (no more "if you miss the bus you're stranded")
Vienna itself seems to be also a nice city for late evening sight-seeing (or beers :D)
Hopefully "soon" we will have confirmation of the dates and we'll be able to publish them :)