Well...
I went with a friend to demo a used Vibro King for private sale... we took turns playing it, suitably impressed. The chap said he was selling it to thin the herd and was hanging onto his Bassman RI (not the LTD series). Out of curiosity we both tried the Bassman, and we found out why he was keeping the Bassman. I kid you not, to both our ears it killed the Vibro King - right from the first note. It sounded much more alive and responsive, made the Vibro King feel middy and small (even though it *was* louder). The bassman notes seemed to have more snap in the bass, throat in the mids and punch in the trebles. Perhaps this particular VibroKing wasn't in full health, maybe the seller had a gem of a Bassman, I don't know. But the poor chap possibly lost a sale by having his Bassman parked next to it. Not to mention it felt like a Blues Jr to pickup compared the Vibro King
That said, being a private residential house we only had the on the edge of breakup. Plus I've never A/Bed the two amps on a bandstand, could be a different story. But I left with a much higher opinion of the Bassman.
EDIT: Just gotta brag... my Juke 1210 and Tone King Comet 40B. Both cooler, IMHO, than the Vibro King.