The mod is helpful if you have a motherboard that (A.) does not have overclocking options (B.) has poor overclocking options/potential.
Some people with systems that are prebuilt, like dell systems, will do the bsel pad mods to overclock since dell locks all usable oc options out of the bios to prevent people from "messing up their systems."
If your cpu can do 3ghz (or more), but you have a crappy board that is making it unstable, a bsel mod may help, but otherwise, it's best to just oc from the bios.