Filter socks are relative to your systems demands and design.
If you have an over size skimmer, went all out on biological, have a large fuge, carbon dose, GFO, etc... socks may be over kill and your system might be lacking the nutrition it needs. Conversely, if you don't equip any number of those things for example, you may need socks to help by mean of mechanical filtration. Ultimately, they are neither good nor bad, you just need to determine if your system is going to need them; and if they do, do you need high micron felt, mesh, etc.
Side note, IMO running socks in front of your skimmer makes the skimmer more efficient by removing larger particles prior to entering the skimmer body.