Thanks for the reply.
I think I'm just a bit baffled by it to be honest. If mr Pack believes in it then that's good enough for me, but I just don't...get it. What I see is a bat with which to get the optimum performance from, one would have to be incredibly accurate to hit the middle. If we are to imagine, rather than the concaving, a shallow but uniform upward gradient from the edges to the middle, i.e a trad bat with big edges and proportionally low middle 'depth' in relation to the edges (think polar opposite of a mjolnir) I fail to see how it could be outperformed by this design. Please don't think of this as unfair criticism, but I'm sure your intention was to raise debate.
It would be interesting if Rob could take time to come here and explain the theory, this stuff fascinates me and others, I'm sure.