Plastic and Nylon Scrubbies/Strippers/Scourers
Pot Scrubbies
Surface area/cu.ft.:370
Upsides: Whats not to love?Fairly high surface area, clog resistance and an easily stackable shape make these an all time favorite for experienced aquarists everywhere.Not to mention they are cheap as hell.
Downsides:If your bio-load is huge yet your sump is less than massive, you will still most likely eventually find yourself looking to add some media with a higher surface area.
Overall:Best bang for your buck as far as bio-media
Scour Pad
Surface area/cu.ft.:150-200
Upsides:Excellent flow rate through media, among the best stacking medias in the "Guide" allow for maximum media coverage in tight spaces.Good as a "filler" media tucked here and there to fill in empty spaces in the sump.
Downsides:Once again with a massive bio-load or very little space to work with you may find yourself wanting a smaller media with a higher surface area.
Overall:Much the same as pot scubbies with some surface area sacrificed for far greater stackability.