Plus points:
Location - excellent as a base for exploring. Perfect for transport links (Karlsplatz), breakfast options (literally round the corner), dining, theatre, the centre, everything.
Apartment layout - very good - nice a spacious, especially considering how central it is.
Shower - excellent pressure and water temperature control.
Minus points:
Noise - bedroom overlooks a busy street, so there is lots of traffic noise, and people walking home drunk, singing etc., in the night (we were there on a weekend). Not recommended if you're a light sleeper. Also, the wooden flooring in the bedroom needs to be replaced - it makes a huge noise with every step, so forget waking up quietly to go for a pee at night.