i prefer neither since i feel strongly that such additives are a waste of your money. they do nothing that a weekly 50 percent water change and gravel vacuuming won't do and the latter is free.
i am with liv2padl i dont like to add anything but the minimum to my tank. i now add ferts for my plants and prime to treat the water when i do water changes. nothing more goes into my tank.
These resin medias have a place in aquaria. Water changes do not remove anything that is in the source water to begin with. Many sensitive species could not survive in some tap water not to mention well water. RO units are expensive and at $5.49 every six months for Chemi Pure, it would take ten or so years to break even with out including replacement diaphrams etc. I wonder how many people use DI units or API's Tap Water Purifier, and then disapprove of this media. Isn't it the same thing?? Maybe I'm missing something. How is using carbon or any resin media, adding things to my water or tank?