Well its been ages since i actually contributed some useful shite around here, and lately i have been amateurishly testing the various fuels currently available to the common joe with an import.
I have been using (and car tuned on) BP Ultimate 98 octane fuel, which is widely renown as a reliable fuel, hence is popularity.
Tried Caltex's new 98 octane a couple weeks ago, no complaints, didnt see any knock over 20 and didnt experience any difference in driveability.
Same goes with United 100 octane, chucked it in an empty tank tonight and didnt see any knock over 20, granted i did only drive around 10k's on it.
I dont give a fat rats what studies show, this thread is for those people who have tested a certain fuel in their car and are happy with it (their own physical experience with it), or are unhappy with a certain fuel (bearing some consistency in mind, dont whinge if you've had one bad tank in 3 years from the one servo). One day we may have enough competition between the various 98+ octane fuels to see some price competition, which will only benefit us!
This can also include those using ethanol based fuels, maybe you have been experiencing a different result with different suppliers, etc. or first hand opinions of power vs cost vs economy..
Commence.