^Beat me to it. The punch you're looking for comes from the power amp. And lots of volume to get the speaker coils moving.
I absolutely agree, nakedzen.
However, with that said, I have to admit I still prefer the fidelity with which the Kemper captures the power amp and speaker dynamics and interaction, versus the Axe-Fx II -- even at lower volumes.
While I don't personally own the Axe-FX II, my buddy does. Don't get me wrong, it is a formidable piece of kit, and if I didn't own the Kemper, I am sure I would be quite happy with an Axe-FX. Nevertheless, when I compare them side by side (which I have done on multiple occasions), the Kemper just "feels" and "responds" like the actual reference tube amp, as compared to the more sterile (IMHO) experience with the Axe-FX. I especially notice this more on crunch and cleaner tones. With the KPA, it reacts just like the original amp, in terms of the attack, note bloom and decay. When I played through the Axe-FX, it just sounded a bit more clinical and sterile...as if it were trying to accurately recreate the reference tube amp, but something was lost in the translation. I don't get that "lost in translation" feeling with my Kemper.
And, of course, the proof in the pudding is actually profiling your own amp, and then make a real-time A/B comparison beetween them (something only the KPA can do). That is when you truly recognize the amazing capability of the Kemper system.
Anways, just some random thoughts.
Cheers,
John