Looking to install a water softener and wondering what the differences are between Kinetico's Premier, Signature, and Essential lines. I realize there are warranty length differences (10 years on the premier, 5 on the others) and that the Essential series is a single tank system. I think I'm sold on the water-metered value, but not sure how much real-world utility a double tank provides over a single one. Any insights on this and if the top of the line system is really worth the investment over the others?