Which will put him down 3 points of AC, relative to a quickened Force Screen. Sure, the extra 0.5dX of damage from an Empowered power (at 7th - 5dX base, 2.5dX from Empowering gives.... 7.5dX, vs. 7dX without empowering; seems manifester level 7 is about the break-even point of empower; with overchannel, that's 9dX with Empower, 8dX Standard; Wild Surge gives 12dX Empowered, 10dX standard) will be handy, but it may or may not be worth the AC bite. It's situational. If you are facing well-spaced archers with fewer HD, the AC could be more important; if you are facing a single BEG, the extra damage could be more important.