i tried it a few years back..made the Herbert take on VHT characteristics. Their cabs are a huge part of "their" sound...so when you plug something different into it...it begins to sound like the VHT stuff. Just MHO.
I've tried my Herbert on my VHT fatbottom 412 a couple of times. As others mention, a lot of the VHT sound is in the cab, those P50's have a unique tone.
While I wasn't thrilled either about my Herb sounding like a VHT through the cab, I am impressed on how tight and crisp those fat bottom cabs are. Super tight low end with the Herb.
Over the weekend, I played my herbert through a Fatbottom cab and wasn't impressed. It was side by side with my Mills cab and there was much speaker swapping go on and the VHT never quite sounded right with the Herbert. Speakers combinations used were (4)G12-65, (2)V30s/(2)Hellatone60Ls, or (4)WGS Reaper HP in the Mills and (2)G12-80s/(2)MC90s or (2)V30s/(2)Hellatone 60Ls in the VHT. There was a Bogner Ubercab there as well and the VHT was definitely last on my list with the Herbert after playing through the Mills and Bogner.