The following is strictly IMO...
Of course X-Drilled rotors would eat up pads sooner than stock ones, they have holes in them, how could they not. If you have big breaks, a) your gonna stop quicker. b) they stay cooler. c) they look cool. But you cant just buy any normal oem pads. You need to buy heavy duty pads. Best to go with the ones that are ratted for the X-Drilled rotors you buy, and from the same company.

ie.. Brembo rotors=Brembo pads.
A good place to buy Brembo's on the Net ... www.nopionline.com