We live in Southern California and if you don't wipe off the water, it'll spot. I also bought the CR unit from Costco. The cartridge refills are pricey. It came new with the tanks loaded and one refill.
They recommend that you don't use more than 15psi water pressure with the CR unit. I had an old adjustable RV regulator that I put on the CR unit and adjusted to 15psi. You'll shorten the life of the beads at higher pressure.
I wash my coach, one side at a time, washing and rinsing as I go. The first rinse, I use the regular water to get the soap off. I then rinse with the CR unit. I have both hoses laying side by side, so it's a pretty easy/quick process. By trying to minimize the CR use as I do, I get about 10 washings out of a tank of beads (one year). So, most should get about two years out of their initial purchase with the refill. A refill costs about $100.00.
