I was an XTOL user and found that 1:1 dilution produced excellent results. I didn't reuse or replenish, as tracking how much extra time was needed for each roll was more hassle than it's worth. I generally didn't use XTOL enough to worry about economy. Since then, however, my processing requirements have risen dramatically but I've opted to use actuance developers. As a result, XTOL is no longer part of my arsenal.