advantage of more expensive escs

[captain harlock]

I do not recommend this at all. What if your expensive controller-God forbids- gets fried as well? I have destroyed one Kontronik 40-6-18, one Futaba MC800c and another futaba controller. My past with ESCs are pretty depressing, but I am the Captain who does not give up that easy. I think your BEC unit has suffered some damage. How about using a seperate receiver pack and see what happens. Also check the way you have connected the receiver jumper too, it might has a role in driving your ESC berserkly.