I started using racing brake fluid shortly after my 1000cc sportsbike revealed its lack of front-end stopping power last year. Before you complain at the idea of using race brake fluid on the road, it fully meets the requirements of the DOT 4 brake fluid specifications, including low-temp performance and longevity. In other words, it's fine for road use where DOT 4 is specified.
I deliberately worked through each brake assembly component on my motorcycle (fluid, then hoses, then pads) to find the problem, and felt the difference when the brake fluid was switched. It helped to firm the performance up a little (it was improved more significantly with braided hoses) but more importantly it helped stop the biggest problem day-to-day for me, a front brake lever having pressure one minute and none the next. I've also used it before on the race track. Coupled with race brake pads, it upped my braking performance loads, making me more confident and accurate with more positive brake lever.
Unlike on the stock motorcycle set-up, I didn't try the racing brake fluid separately, i.e. without better pads, so can't say exactly what difference it made. I'd expect little noticeable change on the road. What I can say is, even in the tropical Thai temperature, the performance remains utterly consistent throughout races, where standard set-up can easily fade. Racing brake fluid is about twice the price of standard fluid but worth it to my mind.