Following up to Louis' post:
I upgraded from the Mk.1 to Mk.II and got closer to what Louis describes the MK.III brings to the table.
I didn't go for the latest driver because I had just purchased mine (used) and didn't want to be without them for the time it would take to compete the cabinet modifications for the new driver and the MK.II version was less expensive (not sure if he has anymore left).
Let me say that I love my Hemptones. This was my first foray into the single driver x-over-less world and wow, what a huge difference. I listen to much more music now.
My advice, factor in the cost of putting in the new drivers (and shipping) of the SuperHemps and see if it's a good deal. If it is, I'd go for it. However, don't forgo getting new speakers from Louis as it may be the overall better deal.
And Louis, I'd be more than happy to give you an true review of the last three 8" hemp drivers. Just let me know.

-Skot