I know what stock means but I have no clue what car he is talking about.

The Scorpion will not stand beat my motor. There is only so much that you can do with a speed 300 motor. Scorpion, Beast, Krystal 3... These motors will all yield very similar speed gains.

The replaceable brushes will allow you to keep your motor running much much longer. Those tuned 300 motors that you are referring to don't last and the brushes are much shorter than the 280 brushes.

You may not like replaceable brushes but they are a good thing. Look at almost every 1/10 motor on the market and they feature replaceable brushes.

1/10 motors without replaceable brushes to most guys are just toy motors and in my opinion so are these 300 motors.