>Also, talking to some that fly the civvy Grob 109, they don't have as many problems with the Limbach engine running funny and the only difference that I'm aware of is the reconfigured fuel system?<
Just for the record, the G109A has the Limbach engine. The G109B on which the Vigilant is based has a Grob 2500E1 engine. I don't know whether the difference is material.