No magic with a CLR? As an acquaintance on Boss GT Central used to remind me (frequently), it's horses for courses. Could just be that you don't like the sound of a miked amp and prefer the tone of a guitar cabinet.
I'm using my Kemper with a pair of Dynaudio monitors and find it super convenient and tonealicious. I understand what you mean by high frequency fizz, but you will hear that even on professional recordings like Lamb of God albums if you listen closely enough. It can be a bit disconcerting, but how you set up your tone makes a lot of difference.
Not too familiar with either the CLR or the Q12... Have you got some frequencies dialled up on them?