As per My observation and study in the water purifier industry.
When you purchase RO water purifier one must keep below things in mind.
1) Source of the Water.
2) TDS of the water.
If you are getting Municipal water you don’t need RO water purifier, But for better taste and complete removal of virus and Bactria along with Chlorine, If you need RO water purifier then you must buy RO water purifier with guaranteed PH value of 7.0 to 8.5 range.
If you just buy RO water purifier isopurewater.com for municipal water there is 90% chance you will be drinking acidic water with PH value less than 6.5. Hence you need to buy RO with added minerals or Alkaline chamber
If you are getting borewell water and water is very sweet doesnt mean that your water is safe.
If you are getting Tanker water or borewell water above 300 TDS, You must choose any RO water purifier with UF or UV or Iodine.
When you buy RO water purifier dont give priority to any brand.
Look at the configuration and after sales service.