I was wavering between 3 and 4 stars. It's a great place to sit and work during the day--very…read morequiet, nice roomy atmosphere, music not too loud. The food is decent but doesn't work hard to distinguish itself. The items on the Tagesmenü didn't look like what I was in the mood for, so I ordered one of the breakfast items. It was pretty tasty, but I noticed that it involved minimal work to assemble; much of it was comprised of sliced vegetables, a piece of feta, and some olives, none of which requires any cooking expertise.
So in short: I might go back here for convenience (good spot close to the Wienbibliothek im Rathaus) but it wasn't a stand-out.