One difference to note between cars and bikes... Computer-controlled ignitions can detect and adjust for detonation. Your car may actually have multiple "tunes" that are used depending on if you use premium (and therefore have no detonation) or regular (which gives you a little detonation). It's possible that your car is tuned for higher octane gas without you realizing it.
But on a basic engine with no adjustment, an engine that runs fine on a certain octane will not run better (and could possibly run a bit worse even) with higher octane. Higher octane allows you to use a more aggressive tune, which makes more power. The higher octane itself does not give more power.
It's like spoilers. Fast cars use them, but putting one on a slow car doesn't make it fast.
The biggest question seems to be whether the improvement from using ethanol-free gas outweighs the unnecessary octane. I've seen quite a few opinions on this, but I'm not sure if there's really an objective test to say which is better. Regardless of anything else, I suggest using
Fuelly or similar to track your fillups. It will help point out issues with how well your bike is running, as well as objectively tracking how many miles you're getting (as opposed to thinking you were getting about X mpg before, but it seems to be down to Y mpg now). It's easy to enter the info on your phone while you're filling up, or just take a pic of the gas pump/receipt and your odometer and enter it later. Simply trying both gas options for a reasonable amount of time will let you see if there are any performance differences
specifically for your bike, though it's going to be hard to measure something like ethanol-induced wear on soft parts.
P.S. Don't listen to me,
I think my bike is a 2-stroke.
