Perfectly located - just 8 mins walk from the Wien Mitte central train station. The space is absolutely beautiful. We were a group of 7 people (2 couples and 3 singles) - each with our own (huge!) room and super-comfy beds. For our group, booking the whole apartment offered us our own individual private rooms while still being able to socialize and enjoy each other's company. In our case, sharing the common bathrooms/showers/kitchen was no problem as we were all familiar with each other. We can only recommend this apartment if you have a similar group booking as we did.
The only drawbacks we could comment on were the construction noise from the neighbouring buildings - although I guess this is only temporary and won't last. Also, as four of the bedrooms are on the street side and just one floor up, you can hear the noise from below so best to keep the windows closed if you want to sleep in in the morning. :-)
In the end, all of us agreed that we would book this place again if we were to return to Vienna. Highly recommended!