Not sure if anyone noticed but the new WE prereq now uses 0.5 gpm for the baseline of restroom lavatories. This will make the mandatory 20% savings more of a challange. These are my calcs on the new baseline based on default use rates.

NA% - low-flow lavatory
0% - ultra low-flow lavatory
5.5% - low-flow shower
1.6% - low-flow kitchen sink
15.7% - low-flow WC
12.6% - dual flush WC
50.2% - composting toilet
7.8% - low-flow urinal
13.7% - ultra low-flow urinal
15.7% - waterless urinal

Since owners seem to hate waterless urinals to the point that I've seen them removed from a LEED building less then 1 year after occupancy I'm going to guess that the most common strategy for getting 20% water savings now will be low-flow urinals and dual flush wc for a total savings of 20.4%. Not too difficult.

I don't see how the 30% point is possible without the pint or waterless urinal and the 40% point will need the composting toilet. Unless I've missed my math. Or use of a grey water system can get the points. This might just spur more use of grey water systems.