These are dual flush, meaning you can use either 0.9 or 1.6 gallons per flush. A normal toilet (including the three we currently have) uses roughly 31.5 gallons a day. The Toto should use 12.3 gallons per day, that could be a savings of 7000 gallons a year per toilet. That's almost a swimming pool's worth of water savings between the two of them per year.
And oh yeah, they look cool.