I'm sticking with NGK's. For no other reason than this is the first time in over 50 years that I have had one fail in a 4-stroke engine.
My 2-stroke engines have had good luck running them and an average life of three years,which is good as you know how hard 2-strokes are on plugs.
I also run them in my Propane fueled John Deere tractor and I run the snot out of the tractor year round. The last set lasted almost 10 years.
All of my gasoline engine vehicles run NGK's.