Who is best Rachel Riley or Carol Vorderman - countdown mathematician?

I have watched the program since 1982 and love Carol dearly. However, I think that Rachel is probably as good with the maths and is certainly very attractive. Bearing in mind that she, like Carol, was a complete necomer to TV it will take her time to become exoperienced but she is making a very good job so far and, I believe, is responsible for the renewed interest in the program.