I think the best softener is one that gives you the longest service free operation and thereby the best is any softener using the Clack WS-1 or Fleck 7000SE control valves. That's because, IMO, the control valve is the most critical part, it is where all the moving parts are. Both of those valves have one moving part in the water stream. All other valves have many moving parts. The Clack WS-1 is the easiest to repair if needed and the Fleck 7009SE doesn't require any control valve specific special Fleck tools as the other Fleck valves require. Both valves have soft water brine refill and variable reserve while the Fleck 7000SE has variable brining. You can find web sites selling either or both by searching for the name inside "".
Quality Water Associates