I have a small refugium on my tank. It is in my wet/dry (if I was more intelligent when I got into this, I would have gone with the sump altogether). Anyways, all of my macroalgae is where my bioballs would be.
Here's a pic of my wet/dry with my chaetomorpha algae on the right hand side (this is an old pic, the algae in there has since tripled in size and thickness). Anyways, I like running the fuge because it adds a lot of oxygen to the water, helps a lot at keeping the nitrates down, and adds a lot of life to my tank (feather dusters, bristle worms, copepods, etc.