I’ve compared side by side 3 Rev C’s (played 4 total) and have compared my favorite of the 3 C’s with 2 Triple Rev F/C mods, a Rev D and Badlander I all had and IME the differences were pretty clear cut and actually bigger than I was expecting between revisions. Sure they varied plenty between the same revisions, but still at least sounded like the same revision overall with their respective distinctive qualities to each
The F’s sounded stale and less responsive vs the C and D and couldn’t be dialed in to really get the same sound or feel. Even if dialed it in a lot brighter than the C or D it still couldn’t get the aggression or grind the same way in those frequencies (smoother/staler) nor the same tightness and perhaps most importantly the feel. At least from the player’s perspective that difference in feel is quite substantial imo. The C and D were also the only Recto’s I really thought were capable of great lead tones when needed (IIC+ for me is still better there though). In clips I guess one can argue they’re all close enough for government work, but in person the differences to me are pretty big. The D I had was pretty damn good, but the C’s were even better. I could be very happy with any of these early Recto’s, any would be at least top 6 for me, but ignorance is bliss doesn’t work for me
I also find, while you generally get fatter low mids as the revisions go up, the Rev C’s have the most extended actual low end IME