They can be modified to use JG fittings and beer line that you probably already have if you are a kegger. Search ebay for the same type of filter but designed for under the sink.
I use one of these caravan setup filters although use standard garden hose and there is not issue with taste/smell. I am using rainwater though, not mains water.
RO water from a supermarket? Can you take a picture next time please, I'm intrigued they sell RO water that cheap? I wonder how often they change over the filter cartridges.
No dramas mate - will take a pic next time. It's a little machine out the front of the store. I stole (borrowed) a few empty 19L Palm Springs bottles from work and I just take them there to fill. I wondered the same about cartridges, but it says on the front that the machine is serviced monthly and they actually have a log of the services and a notice to say when it was last done. Each time I have been it had recently been serviced - no idea whether that means a cartridge change, but the water made excellent beer.