sorry i dont like the poll options, you dont need one but you dont not need one, and it doesnt not matter either way(excuse the double negative).
a refugium is a place where you allow macroalgae to grow, what this does is take up nutrients that microalgae normally need to survive. by limiting the food source from the microalgae you eliminate it. by routinely harvesting the algae you also take out the nutrients that are absorbed by them. a refugium is also a handy place to allow pods to flourish and to put in a fine sediment such as mud to trap detrius and act as another dsb to add to the food webs in your system. there is some debate as to whether or not the amphipods and copepods and such will not go into the pump area, this in my opinion is entirely untrue. i have a baffle that goes over and is located almost 6 inches away from the actual fuge spot and at leats a foot away from any area that pods would congregate in. yet i still se pods crawiling around in my last area of my sump right near the pump. just allow microalgae to grow near the pump. adding the proper species of phyto also helps but any dt's phyto will work. also there is debate as to whether or not a pump will crush up all the pods, i agree that some of the stronger impeller type pumps will kill some of them, but i add all my
frozen mysis to the sump al allow my pump to bring it to my fish and none of the mysis are ruined, neither are bristeworms(the shorter ones) or copepods which i have caught from my fuge and put through the pump, or even large amphipods which i have caught and sent thorough. the other things that the fine sediment would contribute to the display tank will have many advantages even if not pod production. since your tank is a sh tank i think a fuge could help. if you are having a sump a fuge is helpful but the extra water space could also be used for settling traps and micron socks. the fact that such
mechanical filtration would take out pods however would mean that the less mechanical filtration and more natural methods you use the better. sinch sh's generally dont produce too much waste althought the constant feeding would be a slight problem, a fuge WILL aid in live food production and it WILL aid in nitrate,phosphates and nutrient removal, and if a reverse light cycle is used, WILL aid in ph stabilizing. the tough question is which is better for your needs, a fuge or the space for other gizmos. the fuge would be helpful for fish that need to be seperated from the others and share the same water chemistry so as no aclimization is necesary.
in conclusion, a fuge is handy for nutrient uptake and for pod production, but may not make a noticable difference.
personally i like my fuge, it could just be an excuse for another tank but it is worth it to me.