The March 2010 Journal of Light Construction looks at 1.28 gallons per flush toilets, including those qualifying for EPA’s WaterSense label. And they find that the toilets work well. My read on the “winner” of the comparison is the Toto Eco series. And the experience lines up with what I’ve seen, including using a Toto and the green bathroom makeover I wrote about earlier.
One of the more interesting parts of the JLC article, beyond the results, is the sidebar on “How Toilets Are Tested”. Let’s just say you can do it with the bathroom door open.