Waterways STT8 Semi-Automatic Water Softener water softener purchased in December 2015. The softener worked well for about three years, then water pressure began dropping in early 2019. The previous two water softeners installed had lasted over 20 years each, without the resin bed (the filter media) needing to be replaced. The water flow became so restricted that the shower could not be used.
At first the softener being the cause was ruled out due to its age. However, it was eventually identified as the cause, with the resin bed having failed. The resin bed was replaced at a cost of $240 for the resin and gravel, plus one hour of the plumber's time (just over $300). The softener is now working well again. The advice from Waterways is that, for the resin bed to last a similar length of time to those of the predecessor water softeners, a carbon filter must be installed in the water line before the water softener.
A request was made to Waterways to fix the problem under warranty, which was initially refused. After issuing a letter of demand, a substantial email trail and numerous phone calls, Waterways agreed to pay for the cost of the new filter media only.
Whilst I am happy with the water softener, the customer experience left a lot to be desired. I would not buy another Waterways water softener based on my experience.

Approximate cost: $850