Cena beating ironically the big show for that U.S. title at mania was huge . Hadnt cena had his feud with brock by then too in which he came up with the FU to counter the f-5in what way was cena's push comparable to roman's though? by the time cena got the bump up to the main event he was already tried and proven in the midcard and had built his own following. they didn't just decide to randomly strap a rocket to his back and hope for the best. it was more of a sure thing.
in fact cena was more over as midcarder feuding for the US title belt than roman reigns currently is as a main eventer feuding for the real belt.