All the anti-Shockwave talk in this thread... I just GSed Cult of Personality (and The Wicker Man) today with Shock-Pinball-SGuitar. On an especially note-dense song that I'm playing Pinball on, I've found that Shockwave works better for me than any other activation powerup. I'm not about to be able to maintain a jackpot; doubler and bandmate just don't give me as much score as Shockwave does when I'm spending most of the song chasing the pinball rather than chasing notes; and Road Rage and Bottle Rocket actually remove notes from the field in front of me which crimps on Pinball scoring. Shockwave is a perfectly competent companion powerup for Pinball.
Useless for all other purposes, though.