Dr Diff FORD rear disc brakes....What replacement pads have you tried?
These kits use components from the 1994-2004 Mustang.
The 10.7" and 11.7" kits use Mustang Cobra calipers. The newer 11.25" kit uses Ford Explorer parts.
There are a TON of pads available for the Mustang Cobra calipers. EBC, Hawk, PowerStop, StopTech, Raybestos, Wagner, Centric, etc, etc.
For street use I prefer just a regular old semi-metallic compound. They don't necessarily provide the highest stopping power, but they also don't require any warm up to function properly. Some of the fancier pad compounds will give better stopping power at higher temperatures, but they don't work as well cold which is what they'll be a lot of the time if you're just using them on the street.
Ceramics should also work well on the street (no warm up required, etc). I've run them in other applications, I still prefer the semi-metallics. That's not a stopping distance comparison or anything scientific, I just like the consistency and feel from the semi-metallics. But that may just be what I'm used to since that's the majority of what I've run.
On my Duster I'm still running the semi-metallics that came from DoctorDiff with the rear brake kit.