I think the after sales service is very costly and bad. even if you take a AMC(annual maintenance contract) then these guys dont bother to come on a timely basis. Everytime you will have to call them to visit your home and do the servicing. These guys will always say that this part is not working properly and it is not covered in AMC and that you will have to get it replaced. They will charge you a very high price for the part. Not really work it.
You can infact try for another RO in which Shabana Azmi do the ad(sorry I dont remember which RO is that) but the good part is that it keeps the minerals in the water unlike Kent RO