Classic CJ vs ARC battle for your audiophile soul - yang or yin, silver or gold, ginger or maryanne. The ARC gets a better grip on woofers and renders transients more incisively. The CJ has better harmonic nuance and texture in the mids and highs.
The CJ is a wee bit warmish, with a slight caramel coloration, slightly soft in the bottom end. In the long run the VT100 gave me listening fatigue. Ever put a piece of aluminum foil in your mouth? That's what the VT100 series sounded like to me. Happily, newer ARC amps do *not* have this characteristic. If those are your only choices, stick with the CJ.