Which area are you based at? If you are in Klang Valley, can go to Amway HQ and try.

I can provide demo to you without obligation also, bring my demo unit, install at your home, let your whole family try + fill up 2 x 1.5 bottles for you to try.

Then you can experience why it is best source of water.
At the moment, there is a new standard by NSF - 401 Emerging Compounds/Incidental Contaminants

401 is a new standard that come out few months ago - read here
It covers all the pharmaceutical by products that enter the water sources and certify whether water treatment system can effectively filter these chemicals.
Espring was the first (Dec 2014) to pass the standard and at the moment (march 2015) only Espring & i-Water (from Taiwan's  INOVA Green Tech) pass the standard.

Full report - here
PM me for more details / demo

Cheers

At the moment only 2, "quality" at many times can be quite vague. This is why NSF Test Report should be referred to when making a choice.
They do very comprehensive test, using aged filter to perform the test instead of brand new filter, save us away from all the hassles of making a wrong choice.