Hey there,
I actually have the 3 amps you mention. There’s a reason I still all three.
There is something each offers that is unique.
I totally hear you regarding Herbert!! My main “go to” amp for a quite a while.
The 20th is another AMAZING amplifier. Seriously can’t say anything bad about it. It does “its” thing like NO other. My only possible wish would be that more options be footswitchable...so many ways to shape and shift tone and no way to do that “on the fly.” Still, way different and a reason to own both of these.
Now, the Hagen is a different animal again.
It’s a 4 channel Diezel, so you can imagine that there are 3 gain levels and a clean, set up similarly to the VH4. However that’s were similarities stop. Hagen is simply voiced differently. As you mentioned, less compression, more open sounding...nice clean, and great gain.
If you are looking for something to offer you another type of sound, then Hagen might be a good choice. It’s very different from Herbert and XTC 20th.
I don’t see them for sale on the used market all that often...which is interesting. Could mean people simply keep them, like me (I have #10). Or, they just haven’t flooded the market since more hype has always been with the VH4 and Herbert, plus there are quite a few other Diezel offerings. I did have a VH4, yet sold that and kept Herbert and Hagen. I also tried an Einstein a while back, it also moved on.
Regardless, Hagen is a KILLER amp. Many people LOVE them.
It’s impossible to say what’s best for YOU, obviously.
In the end, I sit in the camp of “it’s unique enough to warrant owning one” because Hagen just isn’t like other amps. I really don’t know what to compare it to, that’s why I dig it.
Best of luck Me, to be sure...Diezel satisfies.