I fished the jackhammer a decent amount last Fall. While the components, and fit/finish are "better" than the regular Z man, I don't think the Jackhammer outproduces it. I'd take 3-4 regular chatterbaits for the cost over a jackhammer, and I say that as a Brett Hite fan. I'm no cheapskate and have plenty of higher end lures, but in this case I can't justify the price difference.
I really just wish Z-mans patent would run out so other companies could go back to producing their old designs...