This apartment is perfect if you are travelling with kids to Vienna. Philipp's apartment is inviting, homey, equipped and suited for kids with toys, beds and even a potty! The pictures and description are very accurate and the reality is even better :-)
The location is great. Close to the center but in a quite neighborhood with supermarkets, stores, and some local cafes and restaurants. 2 min walk from a tram station the takes you to Wien Mitte central station in 5 min and to the city's main attraction in 15 min. 5-10 minute walk to the Prater park with great playgrounds and park rides.
Philipp was very nice and welcoming and met us when we arrived. He provided lots of useful information and was very available. Also, according to his CDs he has great taste in music, which is a bonus :-)

Do note a few things, is case they are an issue to you: The apartment is on the 3rd floor with no elevator, there is no microwave and no TV. For us it was fine and we managed perfectly despite that. We would totally stay here again, if we happen to be in Vienna with kids.
(We traveled with a 2.5 year old child, but could have easily stayed there with 3 kids if we had them :-) )