Cip and Krissy were very responsive and welcoming to Vienna from the get go! Their apartment is centrally located and within walking distance from the city centre. It's also very close to the metro stop, their walking directions to their apartment were super helpful. I stayed at their apartment with my parents and two sisters -- so 5 of us in total -- and it was able to accommodate all of us comfortably. I would highly recommend them, especially for large families visiting Vienna.