I'm really on the fence on this one. For almost a year I had a fuge with decent sand bed, snails, rubble, and cheato.
When I added my new sump a few months ago, I took out the whole sandbed, and just left it bare bottom with a few LR pieces and a floating ball of chaeto.
So far, I have not been able too see any lack of benefit. The full-blow fuge was a detritus trap, and due to the low flow I never wanted to disturb the sand bed. I'm not really sure however whether pod production has been affected or not. Both my mandarins still seem fat and happy.
At the present time I have no intention off adding the sand back or adding a cuc back to it. I feel my system may be cleaner w/o another place for trapped detritus. The cheato seems to be enough, at least for my system.