The only super unleaded that is actually refined to its higher octane rating is Shell's V-Power. All the rest are simply standard 95 with an octane booster added.
Shell are also really picky about the tanker delivering V-Power so there can be no contamination.
One of my pals is the Scottish area sales guy for Esso. He says V-Power is the best fuel on the market.
Would be nice if shell v power didn't use ethanol. Esso super is ethanol free unless you are in the SW...