My current water softener is about 20 years old. It's a system from Water Sol and has three components: an ion exchanger on the left, a salt box in the middle and something that looks like a scuba tank on steroids on the right. The ion exchanger and the tank both have timers on top and the timer on the tank has ceased to function. Given the age of the system, I'm assuming it would be more reasonable to replace rather than repair.
What factors should be considered in selecting a new system? For example, is efficiency or capacity a factor?
The system is installed in the crawl space and is in-line right after the pressure tank.