I am not overclocking my p4 3.06 significantly due to the ludicrous amount of money I paid for it ! I am running it at the stock voltage at the moment, so really the DVPRM is superflous to my needs. Gigabyte would have you believe that it is a "miracle", but I think it's probably more of a gimmick.
Anyway, for the hardcore overclocker there might be some benefit, but for most people it's just a novelty.