for mine it does not matter either.. but i like mine.. they are the 7 inch huge ones... they collect a lot of crap, and my sump is in the basement.. i think they help w some pests as well (plus i collect pods to add to other tanks or whatever)
I don't use socks but debris does accumulate in the sump. I vacuum it every few weeks with a small powerhead with a hose attached to the intake and exhaust. I need to do it more often, I noticed a big improvement in polyp extension when I did it last weekend. I am trying to remember to use the baster in there every day to keep the crud from building and see how that works. I figure that if it is blown out daily and kept in suspension it will keep it from getting too funky in there, and either get eaten by the coral or skimmed out.