Systemic Tumbling Syndrome: The faulty belief that shiny brass produces smaller groups or higher scores.
That is a good one. I see you have a humorous mind...
STS denotes the media used in the tumbling operation, 304 stainless pins.
Candidly, dry tumbling with an additive like Nu Finish or any mildly abrasive compound (you can use liquid final rubbing compound as well) will render the outside of the case very shiny and silky smooth.
2 things dry tumbling cannot do no matter how many hours you run it in a vibratory tumbler and that is:
It will not address dirty primer pockets (other than maybe lodging a bit of cob or shell in the flash hole you have to physically remove and...
It will not clean the inside of the case.
STS will leave a matte finish on the outside and THE INSIDE of the case and it WILL CLEAN THE PRIMER POCKETS AND FLASH HOLES.
In my perspective and for what I do, I really don't care if the outside of the case is shiny, means nothing to me, matte is just fine.
For me, what is very important is that the INSIDE of a case is CLEAN and devoid of powder residue and the primer pockets and flash holes are also clean. One clean flash holes and pockets totally eliminate me hand cleaning them with a brush, but more importantly, the inside of the case is clean and residue free which in the case of bottleneck cases is very important as powder residue adversely impacts annealing the case mouth and it adversely impacts seating a bullet because powder residue is abrasive so it causes the bullet to seat harder than a clean case. What I do and what I load, the inside of the case needs to be clean and powder residue free. Dry tumbling will never achieve that.
Finally, with dry tumbling you add an additive to achieve that 'shiny case' but that additive is also deposited on the inside of the case and never removed. I don't want anything inside a loaded case but propellant.
Might not be critical with pistol loads but it is with long range rifle loads.
... and dry tumbling is messy. It's dusty and it's dirty. STS is neither.
The positives far outweigh the negatives.