I did not meet with our guests personally, but from Peter, my co-host, I understand, they are a very lovely couple. I also understood that Dr. Weimer and his wife very much liked the appartment and the environment/location. Unfortunately, there was a mishap with the key, which they had left stuck in the lock inside, when they left the appartment on their second day (Sunday) . After lots of efforts, support from Peter and cost, I now have to fight for re-imbursement. Dr. Weimer told me, he had spent hundreds of thousands of dollars for his 4 houses in California, to make them “idiotproof” …and mine is not. Yes, my appartement is equipped with standard locks, which can be operated as well from inside, as also from outside. I take this as a motivation, to change the lock, so such dismay cannot happen again, even with guests, who are used to life in an idiotproof environment. In the past 2 years, this was never an issue, since people do understand how to operate locks, from childhood. While my co-host Peter stayed over the following weekend then in Vienna to ensure, he is nearby, in case Dr. Weimer and wife will require support again for whatever reason, I was on vacation out of town. Dr. Weimer also mentioned in one of the ongoing correspondences, that it was very difficult to communicate, since I was out of town. True, but Peter was always available nearby and he did all the communication/welcome and support activities - he had not been contacted though. I would not mind much, that the kitchen was a bit of a mess and bathroom was not really kept clean either, but in the light of the “key” issue and the way of not accepting responsibility, I would ask them kindly to look for a different place for their next stay in Vienna.