Hi Frank,
No advantage that I can see unless you would be using very low nitro or no nitro fuel. The "idle bar" glow plugs are just that; they are made for engines that need to idle at low RPM'S. I have seen on this site where some of the stunt guys use them. I assume the idle bar helps keep the fire lit in the engine during maneuvers. I'm sure there are others on here that can give you a better answer than I have.
Dick Tyndall