and got it going last night...it's a very nice unit, and has had good user reports.
It has adjustable back-pressure for the wasteflow, which helps for low pressure situations. I have a well at about 45 PSI, and it works great...getting between 0 and 1 PPM TDS!
Can't beat the price, and they have cheap re-fills.
I didn't want one for drinking water use, so didn't want a pressure tank. I just put the whole unit in my utility sink, screw it into the faucet and let the waste go down the drain...if there are any leaks, no issues.