It depends on what all you're filtering your water for. If you need to remove phosphates and nitrates, that filter won't help, sorry. If you're wanting to remove solid contaminates, microbes, and chlorine, it will work fine. Without knowing what needs to come out, it's hard to say if it will work or not. It will not give you similar results to RO, though. RO filters remove pretty much all impurities, including elements that contribute to GH and KH.
I DIY'd a similar system using parts from my local hardware store--I'm mostly worried about removing sediment, some heavy metals and chlorine. Cost about $100 to setup a 3 chamber system, and the filters are replaced about every 500 gallons.