So, sparring tests skills inherent in self-defense, but doesn’t necessarily test self-defense ability, at least as far as I can tell from the article as is stated here:

from 24fightingchickens.com

Sparring does not test real fighting ability. There is a difference, however, between fighting ability (i.e. the techniques a person could execute) and fighting skills (i.e. the underlying skills that make the execution of techniques more effective). Sparring does compare many skills that are necessary in real fighting: speed, agility, maneuvering, focus with ability to hit targets, ability to read and predict movements, maintaining a strong physical presence, setting people up, timing, footwork, reaction, offensive ability, defensive ability, blocking, countering, etc

I still fall on a net negative balance as far as benefit. The drawbacks outweigh the benefits of point sparring. There is the example of the author ‘demolishing the newbies’ at his MMA practice, but I can’t see why that comes solely as a benefit of sparring as opposed to his other TMA training.