Hey Slash, I feel for you in your search for "THE" tone. I guess we are all doing that in one way or another
I recently acquired both a Herbert and a Mark V. I have been a Mark IV guy for a LONG time before this and I bought the Mark V, based on the fact that I have LOVED my Mark IV's. Now, that said, I also have a Splawn QuickRod head. I sold my old modded Marshall to get that a while ago and I love that too. So, I can only offer you what I know, I don't have any experience with newer Marshall's, Bogner, VHT (other than the 2150 and 2/90/2 power amps I own, and the 2/50/2 I used for a long time). I am surely interested in a VH4, yet it is one I just can't get to, right now.
So, I love each of these amps for different reasons. My question to you is how much do you need ONE amp to do. Obviously, the VH4 is the only 4 channel amp you are considering, right? That is a HUGE versatility piece right there. Herbert and Mark V are 3 channel amps, and the Splawn is 2 channel (like a more traditional Marshall). The thing about the Splawn that moves past Marshall, is its mode switch for the gain channel. You get 3 modes to choose from and therefore much more versatility. You can easily nail tones from vintage rock, a la early Van Halen, to heavier rock and metal. The Mark V has some great improvements, including 3 modes on EACH channel. Again, you have versatility and choices. I am enjoying the Mark V a lot and have put the Mark IV's in the closet for a little while. Not selling, just in the closet
Now, Herbert is just WOW!!! I can get sounds from this amp that I just can't get from the others. Totally amazing!!! That said, as I mentioned, I haven't sold anything else yet either. I am more interested in finding ways to combine sounds and get these amps to work together. Each shines in its own way and I am planning on experimenting with how 2 or maybe even 3 heads can fill in any holes left by the others. I wish I could tell you more about the VH4, however, I just don't have one...YET!!! It is only a mater of time before I am forced to submit to a VH4 as well
Anyway, you seem to have some supporters of the VH4 on the forum anyway, so you don't need my input on that.
In the end, this can't be about others telling you what to do, rather it has to be an individual thing. You might hate my tone, and I can be OK with that
Just kidding...but really, my point is, depending on your needs, you may need more than one amp. Obviously, that's been my solution
Best of luck!! Tell us what you decide and what you find out!
Rawk