I always read these threads with interest, i've used regular grade E fuel since it's introduction in all my gas powered equipment, never had the first problem with it, 4 or 2 stroke engines.
As already stated, i think it has to do with use & mine are used year round around the farm, when not in use for time(mower), a conditioner goes into tank which equals to pennies on the dollar, even the weedwhacker get's used in the winter with a brush blade for fencing & broom for whatever snow we may get.
I do not like the fact of E gas, it is what it is though.
Ronnie