All that is true for any piece of high-end gear. Constant upgrades and revisions. It's why I usually qualify my description of the Herron VTPH-2 as being the best I've heard. I haven't heard any other phono stage equal it (most aren't even close), but I may not have heard the latest editions or revisions to the more popular units. This holds especially true of the smaller companies that are constantly pushing the performance envelope of each other.
I usually suggest that those looking for a new phono stage contact Keith Herron to see if they can arrange to secure a unit on loan / approval. IMO, it's really the only way to be sure.
