I own the ST-85 and I've had the Music Reference RM-10 (original model) in my system. The ST-85 will have greater dynamics and bass, but its best (most natural and musical) sound by far is in its triode mode (where the bass is still very respectable but the power is much lower).
Of the two I'd choose the VTL, but if it were my decision I'd probably seek a more powerful amp that still had excellent sound at high power. The VTL sounds okay, but not great, in its higher-power tetrode mode.
Of the two I'd choose the VTL, but if it were my decision I'd probably seek a more powerful amp that still had excellent sound at high power. The VTL sounds okay, but not great, in its higher-power tetrode mode.