Here's what my research has turned up. Take it or leave it, or use it to buy me old woodworking tools.
1. Most all of the units sold in HD, Lowes, Sears, etc are all made by the same company, and can last, but often don't. Each brand puts their label on it, and has their own plastic containers. Valves are usually PVC or something that embrittles with age. They generally use non-serviceable valves and have parts that are expensive. Their resin is not high quality, and the only possible upside is the cost, which even then isn't necessarily lower than other options. If you're a builder and just need a unit, these do work, but for how long.
2. The high-dollar/high-quality options: These are the rainsoft, ecco, culligan lines. Kinetico is included here, too. Much higher quality in the valves and resins. Lasts for years and years, and usually not too hard to repair if something does break. Parts not available outside the dealerships, with prices to match.
3. Industry standard units: Water softeners are both complex and very simple. All you need is a resin tank, salt tank, and the valves to make it all happen. On the one hand, it shouldn't be hard, but there are lots of ways to screw it up at the same time. The most complicated part is the valve. Some companies specialize in valves and have gotten pretty good at it. All companies can lapse in quality control, but companies like FLECK and CLACK have long histories of great valves. While metered demand valves (that measure your water use, instead of just working on a timer) used to be a luxury, they're commonplace now, and can significantly save on your salt use. The Auto**** (can't remember, not a slur) valves are just ok from what I read.
Sizing the unit is important, but it's not life or death. An oversize unit can have issues, and an undersized unit has other issues.
The only place near us that sells CLACK is 2-3X in cost what a fleck system online will be.
Sites like these have quality units, i'm sure there are others:
Obviously, knowing what's actually in your water will also determine what you need in a system in both size and features.
Cities will put out a yearly water quality report, or your can get your water tested.
As long as you get a correctly sized unit with a long lasting valve using good 8% or 10% resin, you should be set for many years.
This is all just gathered info from many sites and forums. (like any INTP would do)
I've got to figure out how much I'd like to remove the chlorine and decide which GAC (Granular Activated Charcoal) device I'll purchase.
Hello blowtorch and solder, too.