The problem is that even the Porterfield R4s street pads are very hard compared to a "metallic lining".
What you will feel with them on the street is a seemingly unresponsive pad until you get them warmed up.
That's the "s", street pad too. The race pad, you would likely kill youself and someone else with. Those need to get nearly red hot to work at all?
So far I am still searching for a pad. The HD "taxi cab" compound pads may be the best compromise?