I've not fully gotten to grips with TP7.60's PostScript/GhostScript printing, but what I have managed so far is very impressive.
I think it's only fair to note that no classic Amiga is gonna turn out a 24-bit colour prints as fast as a Pentium based machine. Even an 060/66 Amiga is slow. What is clear, the image quality produced by the Graphics Publisher is unlikely to be bettered by a typical PeeCee setup. That's my opinion anyway.
Cheers,
JaX