This is an interesting one !,
I've been trying to bump up the performance of my bike, TM racing 400. One of the easiest ways is to use better fuel. NO adjusting of any sort, simply chuck it in the tank. But this is where additives are causing me problems. There are products like NOS and Millers CVT which according to the bottle are phenomenal and some are not even road legal ! :D HaHa.
But I dont know which to use, Which would you use ??
Also I have heard of people mixing small quantities of METHANOL into their unleaded fuel to boost the octane points, Is this so ! any thoughts would be appreciated Ollie.

Higher octane or additives will make a little boost in performance. Just remember any time you do this you're putting a little more stress on those parts that are used to using the regular stuff. I don't have any first hand experience, but I've always stayed away from boosters...just usually make performance parts changes.

no octane booster here,
only thing i use is in the car and that is fuel injector cleaner, and it helps me get better milage.Goes from 20 to 24 on the high way, so I use it when I go outta town only......

If you don't have detonation (spark knock, pinging, etc.) don't waste your money. I remember reading Gordon Jennings' comment that often his stock bikes beat highly built bikes either because the hotrod motor blows or the rider can't ride what they have. That always led me to try to learn to ride better rather than go bigger or hotter. Besides it doesn't cost as much for me to just try to ride better.