ARC SP6 or 9; Audible Illusions M3A;Couterpoint 5

I've had experience with all three units. I've owned an Audio Research SP-6C and now have an Audible Illusions L-1 line stage, a close relative of the AI M3A. My best friend buddy has a Counterpoint 5.1. I can tell you that the L-1 is clearly superior to the SP-6C. We're talking an early 1980's design vs. a mid-nineties design. The Counterpoint was never in my system but in listening to my friend's system I was pretty sure it was superior to the SP-6C. The Counterpoint vs. an AI M3A? Don't know for sure. The Counterpoint, another 80's design, was way ahead of its time.

Maybe the ARC would provide synergy. The Vandersteen's are warmish speakers and the Counterpoint is a warmish pre-amp, it depends on what kind of music you like. If it's rock-type stuff, you might be better off with a preamp such as the ARC.
I think the Counterpoint is more than comparable with the AI M3, at least on acoustic music. It is outstanding.

I have owned the SP-6 and the M3A. I have heard (but not owned) the Counterpoint. To my ears there is no comparison. The AI is easily the best of the 3--and not by a small margin.