I am looking at buying a used RO/DI Kent Maxxima unit from someone off craigslist. The seller claims its about 3 years old but that he only used it for a few mths prior to selling his tanks and has had it sitting around, we havent agreed on a price yet, however if the tfc membrane is no good or any of the other filters I may be overspending. I am looking for some outside advice, should I see if I can get this unit for cheap and risk needing filters or just get a new aquasafe unit from Ebay that everyone on the forum says are great affordable units??? Is a Kent system any better? I see it has clear canisters and you can get a silicate removal membrane, seems like the aquasafe system throughs in a lot of nice extras. Thanks for anyones help