You've pretty much nailed it except for one minor nit:
> It takes less energy but produces a concentrated liquid waste stream that must be disposed of.
This implies that creating a concentrated waste stream is a problem unique to reverse osmosis. It isn't. No matter what you do you're going to end up with a bunch of salt that you have to get rid of somehow.
> It takes less energy but produces a concentrated liquid waste stream that must be disposed of.
This implies that creating a concentrated waste stream is a problem unique to reverse osmosis. It isn't. No matter what you do you're going to end up with a bunch of salt that you have to get rid of somehow.