Crisp throttle response for sure won't be found using LL.
And, even when jetted nicely, you will see spooge.
When I was using it in flat track dirt cars, my buddy and I would spend so much money on additives to help the 100LL that we could have bought decent fuel to begin with.
Moroso was sending me Christmas cards, as well as little airy kisses and winks.
Now that I'm old and stupid...I think back and realize that I had lots of fun being young and stupid.
Speaking of jetted nicely...I would amost bet money that if you tweek a bit more on your carb circuits, you'd find that your bike likes the 91 swill just fine, and will scoff at the LL. (shrug)