Does dual-flush save much over a WaterSense toilet?

I’d favor dual-flush when reduced flushes would be used regularly and the particular model clears reliably on both settings. If reliable clearing is uncertain - or the reduced setting would rarely be chosen - I’d put more weight on dependable performance than on the lower flush volume.

I’d treat easy bowl cleaning as a practical factor, not a substitute for comparing flush performance. Deposits around the bowl’s water outlets can affect how water reaches the bowl, so keeping those outlets clear may support consistent clearing. But an easy-clean surface doesn’t necessarily make the outlets easier to maintain. I’d still give a model that clears reliably more weight than a small cleaning convenience.

I’d keep the volume rating and clearing confidence as separate checks: the label helps compare water use, but doesn’t establish how a toilet will perform once installed. I’d want the model installed according to its instructions and compare its flushing performance on both settings where possible, rather than assuming the lower rated volume alone predicts a good fit.

I’d compare likely water use over a typical mix of flushes, not just the two rated volumes: count reduced flushes only where they’d be suitable, and include any repeat flushes needed for reliable clearing. That makes it easier to see whether the reduced setting would meaningfully lower total water use.

For a hypothetical household where reduced flushes suit, say, about half of its flushes, I’d compare the savings on those flushes with the extra water from any repeats. If the lower setting often needs a second flush, the net difference could be small; if it clears reliably, the dual-flush advantage is more likely to hold up over time.