I'm pretty new to the sport but I run with some old RC vets at various fields across Nashville. I started running an idle bar because I fly an ancient K&B Torpedo .40 and it needed the bar for a good idle. Then a few other guys using new engines switched to idle bar plugs and they a little better as well. Now I'm noticing alot of the guys are switching. Everything I have inlcuding my Enya .80 runs an idle bar now.