imaging-resource published test shots made with a production Rebel T4i/650D/X6i. The whole ISO range is covered (up to 25.600), RAW files are also available, all samples can be downloaded in original resolution. These are studio test shots, i.e. test shots made in a laboratory setting. Btw, it seems that Canon was really fast to make the Rebel T4i/650D/X6i available: most shops are reporting that they have the camera in stock and ready to ship.