Mario's place was great. There are 3 bedrooms each with a large bed, which is exactly what we needed. Apartment is located very close to the main train station, which worked well for us since we arrived in Vienna by train pretty late at night. There was a small mix up during the check-in as one of the bedrooms was locked and there was no key for that room in the lockbox we used to get in. We contacted Mario and despite late hour he responded promptly with instructions how to get the key for the locked bedroom from a second lockbox. We enjoyed the rest of the stay without any issues. I would gladly stay at Mario's place again when in Vienna!