Actually, it is. The smooth insert is supposed to reduce friction and speed up shifting, quietly. Quietly being the key.
As a bonus, if you are slightly mis-trimmed, which happens more often with a finite number of clicks than in the old days of infinite adjustment, it quiets that down. I am referring to if you flex the frame slightly and it ticks against it. It obviously wouldn't be to hide continuous rubbing.
Sure all-metal works fine. I'm asking if the '04 Record or Chorus works "better" than '03. If not, I'll get another '03 for less, I'm sure.