I started on the boss katana but bought an archon because the boss just wasn't cutting it for me. The katana is portable and has more effects available than my pedal board, but those are the only upsides of it vs the archon for me. Sound-wise the archon blows it away.
This is as one might expect - the Archon is a far more expensive piece of equipment that's designed to do one thing very well, and it makes few tradeoffs for the sake of price point and features.
Sometimes we forget that even a modeling amp has to go through analog amplification stages. The quality of the analog stages matters as much as the quality of the model being pushed through it. The same is true of any audio gear, including solid state electronics.
F'rinstance, there aren't many Neve 1073 mic preamp 'clones' that actually sound like a Neve 1073, because they lack the Carnhill/St. Ives transformers, the craftsmanship, and pricy discrete electronics. Even the original 1073s were transistor, so this isn't about tubes vs something else, but the good ones are made without tradeoffs such as ICs. Anyway, there's a difference, and you pay for it with something like a BAE.
There are plenty of examples like this.
In our throwaway digital culture, the axiom 'you get what you pay for' is often forgotten because it's so darn easy to come 'close enough for rock and roll'. But the good stuff still has a price.
On the other hand, for lots of folks that price isn't worth it, and for others, something like the Katana is still just fine for practice, etc.
"You're an opinionated SOB, Les."
"True. Who isn't?"