As far as I know, the Kappas (and most other eminence woofers for that matter) do exhibit a rise in that frequency range. In fact, that's what Wayne's horn is designed to compensate for by lifting the bass and lower midrange band and then it stops providing an effeciency increase right around the point where the woofer's response starts to rise a bit. The result is a pretty flat response.

I would expect similar results in the upper frequencies between the kappa and the kappa pro. The reason why I chose the former (non-cast frame) was because it had a lower resonance and longer xmax, which better suited the needs of my system.

The Kappa Pro will probably sound a little better, but will become nonlinear before the non-cast frame lfa and won't play as deep. So it's a trade based on what you want. Either woofer will perform nicely up to about 1.5 kHz with a 2nd or 3rd order xover... I wouldn't run them higher then that.

Adam