Advantages to using ESC/motor brakes:
- Motor braking is easier to install, requires less space, and lighter since there is no servo, mount, linkages, brake pads, etc.
- Mechanical brakes can suffer from brake fade during the course of a run.
- Mechanical brake pads wear out from friction.
However, there are several reasons to use mechanical brakes instead, some of which have already been mentioned:
- More tunable, especially when using a center diff. Bias can be set seperately from front to rear.
- If using an autoshifting two speed tranny (like the Revo, Savage, GTP, etc), you can't use motor brakes because of the OWB on the first gear. So, mech brakes are a must.
- Motor braking is hard on the ESC and batteries. When braking, the motor can induce high voltages back into the ESC and then to the batteries. This makes the ESC heat up more and is not so good for lipos (which are more voltage sensitive than NiMHs). If using a high voltage setup (over 4s), you really shouldn't use motor brakes because of this IMO.
- Greater selection of ESCs. Since you aren't using the ESC/motor for braking, you can use aircraft ESCs (many don't have brakes), which are often quite a bit cheaper. You might need a pistix adaptor to translate the throttle signal though...