The more "cogging" you get with the brushes, the more power they will produce at the cost of longterm preformance. Cogging is when you get a brush overlap....all 3 segments of the comm are being touched by the brush. The less cogging, the more efficiency you will have and thus better overall motor life and wear. I've been experimenting with filing off the edges and have had good preformance with it! The comm and brushes last a bit longer and the wear is more even. You might also try filing a "diamond" shape into the face of the brush for a "V2" feel....but just play around with it, brushes are fun like that.
TQ Racing Wire