Here's a
link to a discussion on the Austin board. Guy on this thread sells the fancy specialty units.
Here's
another from this board over the last few months.
I've owned two homes. Both have had the standard Whirlpool softener that you can buy at the big box stores. The first one crapped out after about 3 years. I replaced it myself with an identical unit.
I have a family of four and my three "roommates" use more water than I care to think about. The Whirlpool unit is fine for me. When it breaks, I'll go buy another. I will always have a water softener.
Other folks will swear by the big expensive specialty units. Just depends on your cost appetite.