Well....I run Pro Set at D2 in two different worlds. Its a pass first (and sometimes pass only) approach, and I light it up pretty good, even with sub-par talent. When defending, I've had more trouble defending the I-form vs the Pro Set.
While this may not help you, my thoughts have been that the I-Form was slightly more "potent" than the Pro Set (especially from a running perspective). Your situation goes against what I thought.
In your situation, perhaps it is the "lesser conference" issue getting into the mix and making it seem like the Pro Set is more potent?