"This sounds like a winner to me-if you want cheap soft water for the (shower anyway)"
Our special Crystalline Quartz Technology. Specially cured crystals act upon the water to create a softer, energy-enhanced shower.
Notice that it doesn't actually say "soft water". If it did, they could be charged with false advertising. You will get a softer shower from the loss of pressure through the filter.
Quartz, sand, and glass are mostly silicon dioxide which is a very inert substance that will have absolutely no effect on your water. The only effect will be the outflow from your credit card account and the inflow to their account.