T3i focusing better than T4i

Yes my T4i is faster focusing in Live view, faster continuous shooting mode but that's about it, I really don't see any image improvement, noise is more present on the T4i raws at same ISO, and my T3i focus is more accurate. Maybe I got a bad T4i, but I'm not gonna swap it again... I only have 5 days left to send my t3i for refund, so I'll keep my t3i and eventually upgrade to the next rebel next year !