Does anybody use Stihl Handhelds, but does not use the Stihl Ultra, Amsoil Sabre, or Opti 2? If so what oils do you use, and how have they performed. I have used Stihl Ultra in my units for the past two years and they have been great but the price is outrageous. $65 for a gallon oil is just not right. I would like to switch brands but I am worried about how they will perform. I have read about Amsoil but Im afraid to mix it 80:1 or 100:1 and then use it in a chainsaw, and if I mix it at 50:1 then there is hardly any cost savings.