When I went and saw  Disturbed ,  Drowning Pool ,  Adema  and  Steromud  at the first \'Music as a Weapon \' tour, I moshed. I moshed a lot.
When I went and saw  A Perfect Circle  I didn\'t mosh. Infact, I got seats (though I never sat, nor did anyone else). If anything, I just motioned my body back and forth and got into the "groove" so to speak. 
I have no plans of moshing to Opeth either.