These will flush with either 1.6 or .8 gallons per flush. You will note that they are marked with the half and full markings on the buttons. The standard and ADA version of the Drake expect to be a top performer for commercial and residential use. Crane makes a wall hung 1.6 GPF replacement toilet called the Rexmont . American Standard has introduced their new Cadet EL with an added siphon jet for a better flush action.
Many new homes come with poor working toilets.
Just fair is the Kohler Wellworth. Toto makes toilets seats with a warm water wash called a Zoe Washlet bidet seat . For colder climates, they also make heated seats in both the Warmlet and the Zo Washlet heated model. Panasonic IntiMist Bidet seats Panasonic makes the IntiMist Bidet seat . The controls mount on the side of the seat.