I'm not bi-amping, but I upgraded my Classik with an LK 140 and the improvement is very noticable.
I don't have the specific experience you ask about, but extrapolating from my experience with the Majik, I'm sure you'd enjoy an improvement, and an even bigger one with the LK 140, like Brian has done. But don't assume that putting the new amp on the bottom will yield the best results. Unless a more powerful sound is predominantly what you're after, I'd definitely try using the better amp to improve fine control of the tweeter. Or, you may find the new amp to better the Classik's amp section enough that you'll want to simply use the Classik as a preamp, as Brian is doing.