[ChuckMcM]

This is pretty insightful. I used them at Google as well and discovered similar variabilities. Doing some A/B testing (trust me testing on the toilet is encouraged there :-) I did find that I used less paper, but not 'no' paper. And it wasn't just for 'drying purposes' it was to insure everything had been taken care of.

Another observation was that you got better with the wash over time. Once familiarized with the placement controls of the unit and the 'feel' (sorry) of the action you could achieve better results. There was some interesting speculation on what a 'complete' fix might entail, and one of the hardware engineers put a 'watts up' meters in line with the seat to get a read on its actual usage (about .037 kwH per month),

My take away was that it was an improvement but not a $1,500 improvement (or $4,500 if I wanted to do it to all three toilets in my house). It also increases water usage, albeit modestly, which is sort of anti-california but that was before I talked with the toilet guys who said the water saving toilets only save water on urine flushes since it it typical for solid matter to require more than one flush cycle. (it still saves water but still).