The benefit of these motors is that they will reduce the wear and prolong the motor life. There are two problems, though. First, they are driven by pure electro-magnetic force, and the power required is higher compared to the brushed motor with contacts. As a result, higher capacity batteries are required. The second problem is that brushless motors are more expensive than a regular brushed motor, and only time and volume will bring down the cost drastically. This is the main reason it will take two years or so for brushless motors to become the standard.
Brushless motors provide more precise control on rpm and ipm, and eventually control the torque being applied. In the example of ACDelco ETC tools, brushed motors provide +/- 10 percent of accuracy variance, but with brushless motor, +/- 3-5 percent will be achievable.
Information provided by: ACDelco Auto & Equipment Tools
