I was running the 3.05 Castle link firmware and I have just recently upgraded to the 3.13 version and the 1.2v for the ESC firmware and before I would get a sudden brake effect when I released the throttle nothing that I couldnt handle I had learned no to completly release the throttle but to just go low with it. After the upgrade it is butter smoothand I have learned to drive pretty well without having to use the brakes.
With my 10s and 1515/2y setup I get about 20 mins of runtime driving it hard and after 20 mins the motor is pretty cool @ a ambient temp of 70 degs cool enough you can keep your hand on it guessing around 100 degs. Batteries were a bit warm