I don't own one but I did a demo since my dealer is switching to Stihl from Echo, compared to the SRM-230 I found the power was the same but it was lighter. The adjustment knob was neat but I wouldn't use it, by now I know how to feather the throttle exactly where I need it.
I didn't have any idle or hard start problems, so it sounds like you guys need to make some adjustments to the machines.
07 F150 4.6L V8
Exmark Viking 36"
Echo SRM-230, PAS-266, PB-770T