Are you on septic or sewer? Where I am, we have a state-mandated secondary water treatment plant septic system. The water that goes down the drain is treated and recycled as irrigation water. It's not potable, but it is useable for watering plants.

RO's used to waste a lot of water however now there are several who have a much better ratio. We have an RO for drinking water that is also hooked up to the water coming into our fridge so the water and ice from it are both from RO. It sits in our basement. I would do a little research on the different brands to determine which one uses the least amount of water. Most of them now have a membrane that is usable on both city and well water (they used to have a separate types so the chlorine in the water didn't eat the membrane).

I have a RO system and it is hooked up to my fridge which makes cloudy crescent shaped ice cubes. I was not even aware that different ice makers made different shapes and clarity of ice cubes.

I have a whole house filter, but it's also a softener so I don't like to drink the water. I used to have a RO, but am weighing a different type of dispenser filtration as the RO removes beneficial trace minerals. Just another factor to consider.

The University of Nevada published a very interesting and thorough evaluation of RO systems. Hard to tell the date, possibly May 2009?

Here is a link that might be useful: Selecting a R/O Unit