I've only used the peanut butter powder before. It's tough, because peanut butter is a unique taste, but not overly powerful in mixtures. I would imagine to get a really strong peanut flavor, you might hafta go a little crazy. But I agree with voodoo, maybe try it as the recipe suggests, then see what you think before tweaking it.
I also love duclaw brewing. The dirty little freak is my favorite