I've had a Soirée in the MB for 3 years now. It develops scale only on the front half of the opening at the bottom. It is a strange angle and I don't think I'm reaching this area with the toilet brush. CLR does not work. Periodically my husband has to drain the water and scrape it off with a myriad of tools. I don't have this problem with my other toilets...an Acquia and a Kohler. Thanks for any help or suggestions!