stringreen, it's not VPI's (or anyone else's) attempts to keep improving it's product(s)---making incremental improvements to a model over time---that it's detractors find objectionable, but rather their history of first embracing one design philosophy, then abandoning it for a second of a completely different nature, then a third. And with each new design, claiming it to be the best way to make that component. I myself don't feel that way, thinking that Harry just came to embrace different designs at different points in time honestly, not cynically. One may buy whichever VPI design one prefers. Or none of them!
There are more extreme examples that can be cited, particularly the myriad of different models offered simultaneously by some speaker companies. Making different speaker models for different applications, room sizes, maximum SPL and/or bass extension capabilities is a very sensible and justifiable practice. But to make speakers of rather different design for the same application does not speak well of a company's integrity. A few speaker companies not exhibiting this lack of integrity are Vandersteen, Magnepan, Eminent Technology, and Wilson, perhaps one factor leading to their long-term success.