There isn't generally a "right" type of water that fits the "normal" category. Some water sources contain more salts than others; some include more elements from plant matter; some have more hard water ions and some have soft water ions; some have an increase in concentration of heavy metals, and some have traces of chemicals that could cause serious concern. RO will simply provide you with water that's safer and better for the health of humans than the water that the majority of us drink. There's evidence to suggest that it can greatly reduce your risk of harm from your drinking water, which is particularly important if you drink from a well water source.