Mine does around the same, maybe a little less waste water than Carey's. I'm pretty sure it's pretty much the same across the board. I save my waste water in 5 gallon water jugs and give them to my wife to water her plants with.
I believe, (Carey correct me if I'm wrong) Carey's is a portable unit that you can hook up to a garden hose. Whereas I had to hook mine up under the sink. I could've probably gotten an adapter of some kind to hook up to hose, but I chose to hook it up directly under the sink. Another difference is that hers is a 4-stage unit and mine is a 6-stage unit. That only means that mine has two extra filters, according to the pages those are both: 5 micron coconut
carbon block filters. It says they are to remove chlorine, chloramine, odor, chemicals, pesticides and protect your membrane.
That being said, her is about $35 cheaper than mine and as far as I have heard, she has not had any problems with it.