This may sound like heresy, but Im getting Robert Downeyed-out at least as Iron Man and his alter ego, Tony Stark. The loose-cannon vibe that hooked us in the 2008 original has atrophied into shtick. And after a 2010 sequel and last years The Avengers, isnt it time for this dynamo to move on to dare I say it acting? He wont, of course. The franchise needs feeding, and Iron Man 3 is already a hulking box-office behemoth. I admit the movie has its moments. Director Shane Black zips the action along. Guy Pearce and a slumming Ben Kingsley have fun as the baddies. And Gwyneth Paltrow gets more to do than snuggle up to a metal head. But for all the clanking armies of iron knights on display to dazzle the eager kid in each of us, this summer epic rings hollow. Theres no one home inside the suit.