I have had a couple of makes over the years, starting off with Permutit, which was fault free. Alas spares became difficult to get when my brother left Permutit!!
You can go for cheap and replace often or pay more and have less problems. Try to avoid the timer models which regenerate automatically irrespective of the amount of water you have used.
There are a couple of makes out there which use block salt (much easier to carry and replace) and have twin cylinders which means that you use one cylinder when the other is regenerating, the change over is automatic, so that you never allow hard water into your system. With the single cylinder models there will be a by-pass that allows hard water into your system when the softener is regenerating. That is why they are normally set to regenerate during the night every couple of three days or so. All depends on how hard your water is...
I have had my current softener for 15 years and it has been trouble free - only have to replace the salt blocks every six weeks or so.
Think of it as a long term investment and you will not go wrong.
Think Kinetico/Harvey/Crown - all twin cylinders and all regenerate on volume used. I have not seen any of these makes at a plumbers' merchant!!
