Well, I ride a 158 and I am 5'9" and 150 lbs and a all mountain rider mainly at Mammoth Mt CA. I admit that I am not an extremely technical rider, but I can carve. The A-frame doesn't chatter at my speeds and flexes well in turns. It does well in all conditions that I have thrown at it (powder, courderoy, crud, ice (if the edges are sharpe) Sierra cement). It take it down everything from double blacks, trees, smaller drops and even the park (occasionally). I have Cateks mounted with no obvious signs of stress other than the normal binding marks. I love it for my use!
I hope this helps. :)