I preffer the Blacks because the Red ones feel alot more plastic. The black ones are made out of the nylon string pick type stuff so they feel alot more solid to me and i feel i have a better grip on them too.
Pinched harmonics and artificial harmonics are easy.... I can do the pinched fine with thicker picks a little tougher on those thicker ones though just takes practice...
I preffer the Blacks because the Red ones feel alot more plastic. The black ones are made out of the nylon string pick type stuff so they feel alot more solid to me and i feel i have a better grip on them too.
I also noticed they didn't do it at the Opeth gig i saw in March. Maybe it's just a bit to difficult for them to do live. Sounds good either which way.