This is a matter of personal choice. A softener will improve the efficiency and increase the life of appliances using hot water. It will make lathering easier and reduce tide marks on sanitary ware. Some people with skin conditions, such as eczema, have fewer problems if they use soft water for washing. But if you do install a water softener you should make sure that you have a supply of unsoftened water for drinking and cooking.
This is because:
there is evidence of less heart disease in hard water areas than in soft water areas, although not all studies find this link. If something in hard water protects against heart disease, water softeners might remove this protection along with the hardness
many water softeners work by replacing the hardness with sodium. Too much sodium can be a problem for premature babies because their kidneys are not good at filtering it out of the blood, and for people who are on a low sodium (low salt) diet
soft water may release lead from any lead pipes downstream from the softener
a softener which has not been properly looked after may release germs into the water.
If you do decide to have a water softener we advise that you buy it from a reputable supplier, for example, one which is a member of British Water, and have it installed by a qualified plumber who is a member of a recognised Trade Association, such as the Institute of Plumbing. We also advise that you maintain it in accordance with the supplier's instructions.