CORBON is excellent ammo, relatively speaking.
But, for self defense use, different calibers have different "best ammo brands".
If you Google FBI ballistic tests and "most effective law enforcement ammo" you'll see how a given brand/weight have a percentage of effectiveness.
According to current stats, Winchester Ranger T series and Federal have the best "one shot effectiveness" rating in .45 cal.
Corbon is rated high in their DPX and standard Corbon ammo.
For .40 caliber ammo, Federal and Corbon are at the top.
The top rated law enforcement ammo used in the US is Federal, Winchester, and Speer.
Lesson learned is that one brand may be best in one caliber but not in ALL calibers.
It'll pay for you to do your homework and select an ammo brand that's specifically designed for the use you need.