I dont know that you can get a 'bad' RO
system. Someone may differ with me but the longer I have my Kent Marine RO
system, I have been looking around at different systems on Ebay that are a LOT less than mine and do the same thing. I would go with any of those units - just make sure it has the following or capacity to: 3 stage which would be a sediment, carbon and resin block, and then a High S membrane (which is located on the top of most units.) Other than that, thats all you need. The filters is what will eat your lunch if you have to change them every 2-3 months like I do. I posted earlier that I found a 7 pack of filters (3 sediment and 4 carbons all 5-10 micron) at Sams Wholesale...so get an RO
unit that will allow interchangeable filters..Just my 2 cents worth.