I am going to be different, I have owned several different brands. I really like the 4-stroke Robin, also branded Dolmar 7601.4 or Makita BBX7600. Put 10w-30 oil in the crankcase and straight gas. Easiest starting backpacks I have ever owned. Blows comparable to a Redmax 7000.
A Exmark,New Holland and Red Max equipment user!!