Markus was a great host, and his apartment is just amazing.
It has everything you need - a small kitchen, a nice view and endless amounts of steaming hot water.
It's also in a great location in the old part of the city, which is exactly where you want to be. A simple 20 minute bus ride from the airport gets you there, and other than the airport bus, everything else was waking distance.

I highly recommend Markus and his Viennese apartment, and will definitely use it again when I return to Vienna.