I've had pin negative, cg negative and both negative. My rec. is don't do both. As was said, not a large move, but controlled. I like negative weights when forced to play tight and deep, i.e., around 18 or left without a big swing.
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"I do desire that we may be better strangers." Willie the Shake, As You Like it(III,ii)
"I'll bet that Jesus would have used HIS turn signal!!"