My 3 colleagues and myself spent 4 nights at City apartment VIC staying in Vienna for a conference. The hosts were very friendly. They were ready to provide some useful tips and local advice but checking in and out was very straightforward. No additional charges were counted above the ones indicated on the website. The aparment was large and cozy for 4 people. We arrived late, and ran even an hour late for our initially projected arrival, but the hosts stayed up and they did not even request additional compensation. They were always readily available when needed. We were a bit worried about parking in Vienna, but there was free parking available in the streets around the apartment (No short-parking zone).