Great information and excellent video! I guess if you use an IBEC you can go with a single receiver and ignition module battery.

I don't see that much of an advantage other than if you are really tight in the weight department. A good IBEC looks like it's about $40. You could probably get a decent battery and switch for about that much, so price isn't that big of a difference either.

I still like the simplicity of the two battery approach through. All you have there is a battery and a switch instead of a complex electronic device. But, either method seems safe enough for me. I guess it's just a personal preference.