This is a rather apples vs. oranges comparison. The CJ and ARC sound are different as one can get, and to appreciate one over the other will certainly mean that some part of you likes one type of "family" sound over the other. Both are excellent amplifiers, and will do dramatically different things with the music. Also, keep in mind that the proper comparison is the CJ Premier 12 and the VT-100 mkII, not the lower powered Premiere 11a.
Anyway, that said I'll throw my hat into the ring for the Premier 11. While I think that the ARC amps are excellent, they almost universally leave me cold -- too analytical and lacking in a certain *something* that involves me deeply in the music. For me, the CJ amps are quite the opposite -- easy to listen to, very musically involving, and thoroughly enjoyable. One limitation that I'll have to admit to however, is that most of my experiences with ARC amps have been with ARC preamps (and with Thiel speakers), and likewise for CJ. I do know how the LS16 and VT100 II sound together, but I'm not entirely sure how the combo of ARC preamp and CJ amp sound. My guess is that the CJ provides some warmth to augment the transparency of the LS16. Without hearing it, I'm guessing that it might be a very good combo.
Anyway, just some food for thought. I'm curious to hear your assessment of the ARC/CJ combo, especially if you get the chance to try it out against the ARC amp. For myself, I've been curious how the CJ preamps would do paired up with an ARC amp. Maybe someone out there has a few insights about this.