I have the dual friction version behind my 350. It was fine when I had ~350 hp, but now with 425HP it's not holding it very well.
The centerforce has soft pedal presure (similar to the stock clutch), but I'll be going to the Spec clutch when this one dies. I understand the Spec is a bit stiff, but holds much better.
For a daily driver under 350 HP I would still use the Centerforce for it's smooth engagement and light pedal however.
Russ
------------------
86 SE350 x 4 speed (my way)
86 SE2.8 x 4 speed (all-option restored)
88 coupe x 5 speed (future IMSA 4.3L project)