A lot of BIG trucks (semi tractors) use the metallic disc. They are pretty aggressive and hold well. They also wear the flywheel surface more.

I guess it depends on what you are doing with your truck. If you are using for actual work, and are pulling heavy loads, I'd go with the 'metal' clutch. Any other light-duty use I would use the organic, as they are much more forgiving when engaging the clutch.

Remember 9-11-01--God Bless the USA
JUSTICE, not REVENGE, will prevail

1951 Chevy 1/2-ton Pickup truck