I love the camera and it has much better focusing than the T2i and T3i that I had in the past. I bought two T4i's to have one as a back-up.
In the non-live view mode, the 9 AF points in the T4i are all cross-type while only the center AF point in the T2i & T3i is a cross-type.
In non-live view, the non-center AF points in the T4i focus better than the center AF point in the T2i & T3i even though both the T4i and T3i are supposed to have the same high-precision cross-type center AF point.
In live view, the T4i also appears to be focusing much better than the T3i. Surprisingly, in the quick mode AF method, the live view in the T4i allows the transfer of the actual AF points not just a general moveable area that is available with the T3i in the live view AF mode quick mode.