I have had an original Aquia for just over 2 years and I'm generally very happy. It does seem to "mark" more easily than other toilets I've owned. The one problem I wonder if others have had is a mineral buildup. I can generally remove the buildup with some CLR and elbow grease, but it's frustrating that I've had to deal with it. It's likely caused by a habit of not flushing urine to further conserve water (we picked up that habit during a drought last summer). I've asked the family to use the 1/2 flush since the first cleaning, but the buildup seemed to return within a few months.
Anyone have any ideas or suggestions? Thanks.