The Vipair thread rivals the Viper Chicks thread for # of views and # of posts! Its epic, a blockbuster of internet gab.
Vipair re-routes the air intake away from the Naca duct, and draws it from down lower, from the grill area, I think.
Joe117 and others "took them to task" about the claimed HP gains. Unless you have a wind tunnel, there is no way to recreate in a controlled environment actual conditions of use, so dyno runs done with only cooling fans are not telling of any possible gains you would have from the incident wind out on the road.
Lots of variables, made for some interesting conversation!