My understanding is off road use only means the product has not been certified and has nothing to do with quality. I had a set of Wilwood big brakes on my 2003 Cavalier, and they were definitely effective, so effective that I had to be aware of anyone behind me when doing a hard brake. I got over 30K miles on them but when it was time to get rid of the car I put oem brakes back on.
My point: has nothing to do with quality and everything to do with if the maker has gone through the process of proving to DOT/EPA the product meets their standard. If one plans to sell the product in the thousands than the maker should be certified; if in the dozens or fewer, who has the funding to go through the process, or even more pertinent, how many retail consumers have the money to cover the cost?
I have got to get the FNADER license plate for my Corvair.
Laborsmith