I did the VPI upgrade route too starting with a VPI Classic with unipivot 10.5 standard arm and ending up with a Prime with 3D arm before moving away from VPI. I did feel that the printed arm was significantly better than the aluminum arm, both of which were unipivot.
My next move was to have Greg Metz rebuild my Thorens TD124 with custom bearing and platter and mount a Reed 3P arm on it. This is where I came to believe that the tonearm has a tremendous role in ultimate SQ. There was a huge leap up in sound quality-more meat to the bones, more integration of sound, just better music, all using the same cartridges that had been in my stable-Benz Gliders and Ortofons. Since then I have gone up in the cartridge tier ranks with a VdH Crimson Strad and Lyra Etna Lamda. Then I added a Greg Metz Garrard 301 with upgraded bearing and platter and with Reed 3P and now I am off the upgrade path for good (as it pertains to drives/tonerams).
I have mixed feelings about VPI. They are good in a lot of ways and have shortcomings. The tonearm designs are not up there with the best, but that is just my humble op.