think of it this way:

Having foward-brake-reverse all on your esc can be compared to flickering a light. When you flicker a light alot, you drain tons of electricity and you will notice the difference on your electric bill. When you keep the light on constantly you will not drain nearly as much power. Same thing with the esc-motor, it will drain your batts faster, but more importantly it can damage your motor and esc.

To sum up the analogy, having foward-brake-reverse will last you, but having mechanical brakes installed will increase the escs longetivity. But I wouldn't say your esc will die because you had the esc do all foward-brake-reverse functions.

Email BK on the subject, or search around the posts (someone quoted what bk said)...that may clear things up.