I disagree. Are you trying to sell something, or have you actually had real world experience? Most water filters ARE effective taste wise. As for mineral/health wise I don't have scientific tests. The problem with mineral/health wise is that the location where you live could be a large factor. Whether you have well water, delivered water, distilled water, etc. could be a factor. These are big factors.
I've used several on tap and off tap filters, brita, pur, carbon filters. I noticed they all did one thing: taste was significantly better. All chlorine taste was gone using all filters. The off tap brita filter seem to be slightly less effective taste wise than on tap.
Another question is plastics. All these filters seem to be plastic enclosed. Since the water sits in the filters all day, what effect does plastic have on the water (plastic can be bad, lab tests show it may cause cancer, certain plastics, all plastics, I don't know).
There are many factors to be considered, but I do know ANY filter will make a huge difference, as I've travelled to many different places where I get turned off by the water: as soon as I add a filter the water tastes neutral, like at home.
Another factor is the question of what happens when a filter is clogged. Is it more effective, less effective. It could actually block minerals from getting through. In some cases, this could be good, if you for example already were getting enough calcium in your diet .. it could also be good if the calcium in the water is low quality (cheap, limestone since water companies are in for the business). Or it could be bad, if you are low in calcium, and your body needs any kind of calcium (eve limestone, if your body is willing to accept it.. it's still better than no calcium). Other minerals apply to, I am just using calcium as an example.