I'ce been curious about the Duravit Happy D. close-coupled elongated toilet as well. The couple of inches that it might save are very beneficial in a small bath. But how does it work? Some comments on-line suggest the water use has gone from 1.6 gal to 1.28 gallons per flush. The Duravit website, however, is about the worst when it comes to supplying information about their products. No info on water usage, seat height, seat shape, standard rough-in distance, or installation requirements/procedure. On the other hand, a lot of their stuff looks great. But how does it work?