We rented an apartment through Century 21 for almost a year. We were very happy with them in the beginning, since they seemed to show a genuine interest for us, and seemed to do their best to help us find the right apartment. The actual renting process then took quite a while, and we have since experienced that they seem to be a bit too busy, and do not have the opportunity to take their time to help their customers to the extent they need. For a real estate agency I do think that they are being serious, all be it a bit too busy.