A great tube amp via a great guitar cabinet sounds huge - nothing can beat it.
I still love to play my tube amps - just for the fun of it.
So why a Kemper when I still use conventional gear?
When I record anything its much easier to use my profiles - they sound better and more consistent than trying to get the same sound each time.
Because I can spend much more time while creating the profiles to optimize the complete setup.
Another advantage - I can play anywhere, at any sound level, even at the mid of the night with headphones - and can record the profile of my amp without any noise.
So I see no reason to use anything else than FRFR in my studio.
What would I recommend for live playing?
FRFR as well!
Why?
The advantage of the Kemper is to simulate the complete signal chain incl. the cabinet, mic ...
If I would use the KPA with direct profiles and a real cabinet - I would use only have of the full package.
And the main disadvantage is:
In case you only one guitar cabinet with the Kemper - it will sound like many amps via the same speaker.
Is this a bad thing?
It depends.
A Rectifier profile via a Recto 4x12" with V30 speakers may sound great.
A Marshall profile via a Recto 4x12" with V30 speakers may sound ok.
But a Fender Combo profile via a Recto 4x12" with V30 speakers will sound like sh..
If you still use a guitar cabinet with the KPA - consider the next step to get full use of the Kemper - go FRFR 
