My city is in the middle of the worst drought in recorded history. My showers are typically under 2 minutes and I have to shower with a bucket to catch otherwise wasted water to use to flush the toilet. I also shut the water down when I am wet enough so I can scrub myself without having unneeded water flowing then start it back up to rinse.
Plus, water is damn expensive!
Who here really has the time to stand, think and waste in the shower?
One way to avoid wasting water is to turn off the water while scrubbing. Only use it to rince yourself before putting on soap or to get rid of soap!
I have both a shut off near the mixer and on the handle and I love it.
Now that would be great!