I raised this as a query when I replaced mine. As many have already said not being "road" pads doesnt make them bad pads.
What would be interesting is if it would invalidate your insurance, if so and you fit them ... i wouldn't go shouting about it. I went for Reg 90 approved Cosworth SM pads to be safe from Horsham Dev (Basically best I could get staying within regulations).
I checked my pads when they arrived and the approved symbol is small and would eventually rub off I believe so how you would go about proving or if anyone would check is another matter. I doubt DVLA or Police will strip your brakes down to check!!
Maybe someone form Sky, Chris Knott etc could comment on insurers position?