Basically it should give you a little longer time between clean ups on your big filter. If you have a sand filter and can backwash it, then it might not be a big deal to clean it. I have a cartridge filter and when it got full of big stuff, it was a major pain to clean it.

Keeping the bigger stuff out will keep your filter from getting clogged and operating better. If you do not have trees or other plants that drop a lot of stuff in your pool then you may not need skimmer socks.