I'm not planning on getting one any time soon, but I do want to learn a little bit about them. In the long run, I'm sure any RO system would easily be more cost effective than weekly CVS trips for gallons of distilled, but I don't get what exactly differentiates one system from another.I've seen counter-top filters for less than a 100 dollars, and under-counter systems around 400 dollars.
What's the difference in the water that comes out? What should I look for in a system? What's the best? What's good enough (for CPs)? What should be avoided?