Worth it, true
While not a scientific way to measure, I just plug the drain in the laundry tubs, see how full it gets from Maytag to Whirlpool to GE. Tag and FF use about the same for a fill, but then the GE spray rinse is more plentiful than the Tag. But when you look at the final rinse water, so nice and clean, it's worth it. My dirtiest stuff, and towels/blankets/jeans that retain water and need plenty of rinsing, always go in the FF. And from what I've seen, it has better turnover then the Maytag. Then I watch the final rinse water in comparison to the Maytag, and I know I've got the cleanest, best-rinsed clothes around, worth the excess water.