I have used both of these blades. The Astra SP would be the winner... For me. Can't speak for everybody but the Astra SP is a great blade with good consistency.
I need a smooth blade or i get weepers. I get weepers from astra SP in my Rockwell 6S on setting 4, and usually one or maybe 2 small ones on setting 3. I don't from gillette wilkinson sword.
I like both blades in my Techs and Superspeeds, but in my Maggard MR1, the Gillette Wilkinson is the clear winner. Smoother, more forgiving, and less irritating to my sensitive skin.