Excellent hospitality thanks to Aljona and Flora (the other tenants were not around during my stay), very easy-going too. Nice and super tidy flat in superb (peaceful, pretty, rather central and well connected) location.
I would definitely stay there again!

P.S.: Google maps does not get the public transport right in Vienna yet, but Aljona&co. are very helpful! You can buy tram tickets in tobacco stores.