One of the things I miss from playing a Kemper (through a cab) rather than a traditional amp is the lack of air movement caused by playing. Is this something Kemper would ever be able to incorporate into the software or is something physical missing that means this could never be achieved?
Thanks! 
Maybe try to add some low end on the eq - to push your speaker to the limit - and of course Master Volume to the MAX!!!.
Can you define "pushing air" a little more for us?
At the end of the day, your KPA is making a noise and playing it through the speaker. Your guitar amp is making a noise and playing it through the speaker. Speakers don't care where the noise comes from. In theory, the Kemper and the amp should be making the same noise - if they aren't, it might be the profile you're using.
This is just something that one has to get used to IMO.
New technology, but some people just want the old way they grew up knowing.
I promise you this, if you can adjust to this one aspect, you will have better tone than ever and never miss the air again.
I never got a compliment on my tone from all the gigs I did with my $3,000 rig with the tubes and 4X12 behind me growling.....
But I get rave compliments every gig now just going through the PA in stereo with my little CLR in front of me and I am loving every minute of it.
That would be what most of us call "bass".
It's probably worth asking how you're running through your Powerblock. The ideal solution for a modeller is to use the Crate's FX return, so you can bypass the entire preamp/EQ/etc section. Downside is you only have your Kemper's volume knob to work with.
Yep, chances are that too much circuitry after the Kemper's out kills your sound. Try and exclude any kind of useless circuitry, a Lokasenna suggested.
Also, pushing air (whatever it means) is a matter of interaction between the power section and the loudspeaker(s), it doesn't have to do with the amp simulation.
The Kemper, as a pre, has got a spectacular perceived impulsive power, and a very low noise level. There's nothing more a pre could do 
The Powerblock is not a high power linear poweramp. That influences what you are hearing quite a bit.
What amp/cab are you used to feeling that air movement with. I bet if you profiled it and drove the cab at the same db with the KPA it would feel like it was moving just as much air. That would be a hypothesis on my part 
Speaking of moving air.... Check out this video with our own Kemper forum, JerEvil. The camera will show you air movin!! About 15 seconds of video at 6:30 is all you need.
@Johnny333, I understand how you feel some type of difference between the KPA and a real amp driving a 4x12 but believe me that the KPA with the right power amp will definitely make you smile with the same air moving.
LOL
LOL
In the name of holy science , I tell you that is not the KPA is pushing Air but speaker.
And not pushing but pulling and pushing
Try a XiTone Cab. It's pretty damn "airy".
And I have a JCM800 combo sitting right next to it for comparison.
Can you define "pushing air" a little more for us?
At the end of the day, your KPA is making a noise and playing it through the speaker. Your guitar amp is making a noise and playing it through the speaker. Speakers don't care where the noise comes from. In theory, the Kemper and the amp should be making the same noise - if they aren't, it might be the profile you're using.
Define "pushing air" - I'd like to respond here - I remember when CD's first came out - I thought the sound was too sterile i.e. 2D vs. 3d - depth, richness, open sound of quality vinyl. For me, the Kemper reminds me of that - it sounds like a flat 2D tone vs. 3D - so 3D translates to "pushing air".
