What's the weak link in my Analog chain?

For no cost you could start with confirming cartridge loading and gain and alignment. I agree that proper isolation is always good. Beyond that, I'm not really familiar with your components.

Thnaks for the responses, all. I think part of the problem might be break-in. The Chinook was brand-new in a sealed ox when I brought it home (Ihave teh option of buying it or returning it ot the dealer who will use it as a store demo). I have about 70 hours on it now, and things have gotten progressively better over time. Also, I went from 200 to 250 pF on the capacitance, which seemd to have cut down on some glare without sucking too much out of the high frequencies. 300pF seemed to darken the sound too much. I played with VTA a bit, by ear, I think I'm in a good spot, not sure if I'm much different than where I started.
Omsted, I wonder about the tonearm, too. Looking at it, it's a wonder that it works at all, much less well. The actual arm is just a 3 inch long piece of stiff wire; everythign else is a fancy, jiggly pivot. In terms of lacking body, though, that's the one area I think I'm surpassing my digital right now. Whether it's a case of all the different colorations cancelling each other out, or what I don't know.

The worst component in that System is the Arm.

I would have to agree with several others. The Souther is a poor design, even more poorly executed. I'd be willing to bet that, ironically, it's causing the classic symptoms of old time digital - constriction, harshness, and several other forms of auditory irritation. If this were mine, I would ditch the arm immediately.