Unbalanced to balanced VPI junction box change?

Pbnaudio is right in that you should be able to swap out the junction boxes. You should be able to use the Nordost you already have in the tonearm. Looking at your system, you show a Sim phono stage. Its fully balanced, of course, so it does make sense to switch to balanced on the TT. If it was my system, I would do it. It shouldn't cost anywhere near $1000 unless you need a new cable to go from the TT to the Sim.

"This is because a true balanced line connection has that much immunity to interconnect cable artifact. So no worries!"

Are you talking about just tone arm cables, or all balanced cables? On fully balanced components and IC's, I can definitely here differences.

Atmasphere,

"IOW what we are talking about is the ability to control or 'swamp' the individual characteristics such that whatever makes it sound good or bad is no longer relevant, instead the technique is going to force the cable to do its job without editorial."

I have a lot of hands on experience with audio but nowhere near the technical knowledge that either you or Al possess. Assuming the above statement is true, are there any tradeoff's in sound quality? When you say "swamp" or control the signal so that the cables no longer have a sound of their own, is there a penalty to be paid in another area for things to work like that? Maybe less detail or resolution, dynamic contrast, that type of thing. The way you explain it, it almost sounds like something is being forced. Please keep in mind, I'm not saying you are wrong. I just don't know. In my experience, when you make changes, there's usually some type of trade off. At that point, of course, the subjective comes into play in that you pick what you are willing to trade, and what you need to keep. I'm just trying to figure out if you loose anything by going with balanced standards.