^^^^^ This. There are some famously stable, beefy big mountain skis out there with no metal (go ride a Kastle BMX 108 or Moment Belafonte or Head Supermojo 103 and report back), and some meh one's with. Reasons, far as I know: 1) Stiffness is determined by the cross sectional area of core + type of wood, + amount of fiberglass and/or carbon. Metal dampens things, allows similar stiffness with less cross section. But it's not the primary determinate of stiffness. 2) Design matters. You can take skis with a lot of metal, put an odd tip or tail or sidecut on it, and it can become quirky or unpredictable depending on you and your terrain. The new Cham series from Dynastar may fit this bill, and the Rossi Super 7 does for sure. A few folks (like a recent reviewer here) would say the flipcore skis from Blizzard also tend to change character depending on how you ski them, while most would prolly say just the opposite. IMO the divergence of opinion is more revealing than the actual outcome; design trumps construction.
Bottom line: Get the ski that works for you, don't fixate over what it's made of.