I just got my Hermansson Marshall 5 gain stage, single channel, with all the options recently, and it became one of my all time faves quickly.
It's the only modded Marshall that does sound like an amazing sounding late 60's early 70's Marshall, when the the Hermansson gain is below 10:00 and the switches are off. Then, as you add the switches and turn the knobs, you can make this thing sound like from early live AC/DC to Meshuggah, without the need of a external boost or eq. And when it does the Meshuggah thing, it does it 100X better than the fortin amp with the 33.
So, it does the old Marshall thing is spades, and I have a 65 JTM45, late 66 JMP50 and a 66 JTM45/100, all originals, to compare the Hermansson with.
It does the 80's thing insanely well. Even the AFD tone this amp does it incredible well. Not to mention it can do traditional trash metal to perfection.
It does the 90's thing perfectly, since the low end can be as air moving as the Rectifier series or VH4.
And it does more modern stuff better than most everything I heard, because of how you can shape the EQ, making the attack and response of the notes faster or slower.
I do own some decent high gain amps, and been through way more hg amps than I wish I did, and the ones that are the most pleasant to play, that feels like the amp interact with your fingers and the guitar, are the CCVs and some of Mark's mods. My 2C+ and the Larry Dino are close seconds. The Hermansson I got went straight number one, right there with the Cameron stuff. Even with the gain backed out a lot, and the Tight control maxed, the amp plays by itself.
It's the amp that I have been playing 80% of the time. And I'm not a great or very clean player, so, I do pass on amps that, even sounding amazing, do feel stiff.
The Hermansson, on the other hand, makes me wanna play guitar all day.
So much that I'm already getting a 3 gain stage mod and will be on the list for one of his own amp.