I'm the same as Rixington, but in my 650. E10 most of the time, E5 occasionally but around November time I always use E5 & fill to the brim before I get home & park it up, just in case it doesn't get a run for a month or two.
There is very little difference in MPG, again on my 650, between the two & I can not tell if it runs better or worse either.