I use a 110GPD RO
system from Filter Direct. It has the pressurized tank, which I think is nice. It holds about 3 gallons, so those first few gallons come out really fast. Without the water coming from the tank, the system takes a long time to fill up the bucket. I just fill 3 gallons, wait a couple hours, then fill again.
I have a 46gal tank and do approx. 5 gallon water changes. The RO
produces plenty for me. The tank is also handy when I need drinking water, or when I want to top of the tank real fast for evaporation.