We only stayed one night but it was great! Our flight was delayed but Maureen was very responsive and met us later than expected with no problem. She gave us some tips and showed us the relevant areas on the city map.
The place is clean and cosy, there's a comfortable bed, sofa, a big enough table, and pretty much all the ameneties you need.
I would say the only problematic part may be that there's no separate shower room with place for towels, some personal shower amenities if needes etc. Was no big deal for us but maybe for some people the privacy is more important.
The location is great, a short walk from Wien Mitte station which has direct trains from the airport and to other parts of the city. We didn't get the chance to go by foot to the inner ring but it seems very close too. Also the area is very nice, beuatiful buildings, local restaurants and so on. All in all we are very pleased and would recommend :)