I completely agree with the OP, I have never been able to make the axe II sound good without the cab sim turned on.
I found it much easier to leave it on and make tweaks listening to the sound through the guitar cab (an early 70's Marshall with 90's 25w GB's).
When the sim is off, it sounds like it is broken to me. I'm sure I don't know what I am doing and my sound is probably over-processed,
but, at the end of the day, it is a results oriented business. And so for me the sim stays on when I use the cabinet.
That being said, I do prefer to use FRFR monitors.
I have taken to the practice of using the real guitar cab as a cool looking table for the mini rack with the axe.
If I turn the cabinet on, I run it through a clean power amp and tweak the EQ of Output 2 to match what I hear differently between the cabinet and the FRFR.
I can get it pretty close unless it gets crazy loud, and then the guitar cab starts to break up. Then its best for me to use both and keep the volume of the guitar cab
reasonable.
In short, I'm a mess. But I like using the cab sometimes. It is definitely psychological. How can you play an old Judas Priest song running through the P.A.?
Doesn't anyone miss a full stack behind you? I cut my teeth on that stuff. Maybe its ridiculous, but I miss the old days.
I think there is a real need to make the speaker output portion of the axe show a lot cooler than what is currently best practice. I want FRFR sound from a beat up vintage
cabinet. This can be done I would think. But turning the sim off doesn't fly to my ears.