ORIGINAL: John Murdoch
And, if for some reason, your receiver looses power in flight, the engine shuts down. You can have all the manual "hardware" installed i.e. choke servos, throttle servo kill positioning etc. but if you loose power to the receiver on one of these systems, you'd better hope your last opertating position of the throttle servo wasn't on full throttle.
I've been using Robert Richie's Smart-Fly for a couple of years now. I won't have a gas motor without one.
Thats the EXACT reason why I have them

All the other methods are great as long as you have the power to use them.