The optional front brake makes a difference in handling by not only giving better braking but it also settles the rear end under braking allowing better control entering corners. I use the standard front brake caliper and disk, only replacing the pads with 1/8 buggy pads when they wear out. You can use the std brake cable until it breaks then I upgrade to push bike cable using an antenna from a buggy as an outer cable. Remove the adjusters from the caliper and the servo end and drill the hole in the red caliper brake actuator slightly bigger. For stoppers I use throttle brake linkage ones again from a buggy. I use the hole closest to the servo centre for more leverage and more power in the brakes. Plus its easier on the servo. I use the std brake servo and dail in as much or as little brake as I want with the brake mix percentage. If you happen to bend the disk remove and sandwich between two thick flat pieces of fairly hard wood give it a few clouts firmly with a large hammer until the disk looks good.
To set up the brakes leave the servo horn off to start. Set up the cable as per instructions. Turn on the radio and bike ( disconnect one gyro ESC wire to stop the gyro spinning up ) turn on the aux channel switch on top of the radio. Go into the brake mix ( no 11 in the menu ) and turn it on and set this to 110 to start. Go into the EPA settings and set channel 3 high end to 120% and the low end to 0%. Fit the servo horn getting rid of as much free play in the cable as possible without causing any binding of the brake. Spin the front wheel and then adjust up the low end until the pads just rub and back off until the wheel moves free. Use this low end EPA adjustment to keep the pads close to the disk. As they wear adjust this until you run out of adjustment then return the setting to zero and either adjust the cable or the servo horn position. Check and make sure the pads are still ok. Final setting of brake strength is done with the brake mix %. The higher the % the greater the strenght of front brake. Try not to use over 110% with the std servo. Just a tip for slippery dirt you don't want either the front or the rear brakes to completely lock as this only causes the bike to get out of control. I also back the rear brake off slightly to reduce locking on the slippery stuff. I set my EPA at 95%.