Used the JG-2 for a few years. It works fine, and I was very happy with it- until I tried the TPC. I don't know about "rounding out the tone", to my ears has something of a hi-fi, crystalline vibe to it. The highs seem a taste sweeter with the TPC.
"There, in huge black letters, was 'The Grateful Dead'. It just... cancelled my mind out."-Garcia