I sold my R3 last summer, but performed a good bit of fuel testing on it and on many bikes - 87 octane works fine. In the heat of Summer, Premium 91-93 octane pump gas can make a very slight improvement in peak power numbers, but can slightly reduce throttle response at lower engine speeds. Engine temps have a larger effect on output.
There are a couple of oxygenated unleaded race fuels that can add 2-4% power comparing peak power numbers, but a bit more above and below this rpm. The better oxygenated fuels like R-Tech Outlaw or VP MR9 need to be tuned to run in the R3. I have not tested the new XXX Racing unleaded fuels, but they look promising, and a good bit less expensive. Some oxygenated race fuels do nothing but cost a lot.
E85 pump blends and custom E85 and E90 blends can easily make 4.5% and larger gains throughout the power band, but custom tuning is required, and for some, larger injectors. The correct E90 blend can make more than 6% gains, will run cool, and can be very cheap. IMHO, ethanol is the cheapest bang for the buck when it comes to fuels.
I hope this helps,
-Wayne
POWER-TRIPP Performance
http://www.power-tripp.com