i dont pay for either one, but imo rivals has better rankings and a much more organized website. the one thing scout has is Mike Frank, who might not even be there much longer.
I was banned on Scout for calling out a certain poster who is a total prick and thinks he owns the site. BlueGraySky didn't like me picking on his buddy so I told him what I thought about his site so he banned me. Anyway Rivals is better IMO, and not just because I was banned on Scout, they have better content and the message board has much better info. This is still my preferred site when it comes to recruiting and talking ND football.