Sounds like marketing bs (regarding to the pump above), for $22 I'd be surprised if it works better, but sure would have been nice to get some measurements with this one considering the price. Did you buy it yet and do you use it already?
If anyone is going to test again, I'd be very interested in the DO in a rez in which return water drops/falls from 10" into the rez, for example in an Aeroflo-like or NFT system, and whether that would add something to using air pump + bubble stones.
If I ever get one of those meters I want to try some different types of waterfalls for the return water. I got a water dispenser sort of thing for my cat, it's basically the top half of a sphere with a small pump inside that pumps the water through the center to the top which then surrounds the sphere with a thin waterfall. Not sure how effective that is, probably more about keeping it to a minimum level than adding oxygen, but it significantly reduces the sound as well. If I place the top half of the sphere about half an inch below the return exit, and still half it a few inches above the water level in the rez, I could have a thin hollow cylinder of water drop back in the rez.