As per Canon's usual practice, the downloadable full-resolution JPEGs have been generated from CR2s converted in RAW Image Task, Canon's software that closely mimics the camera's internal processing. This means that the files almost certainly look less detailed and more smoothed than if they had been converted in Digital Photo Professional instead. As a result, they're probably not indicative of the level of image clarity the EOS-1Ds Mark III will be capable of. Unless you intend to shoot in-camera JPEGs mostly, in which case the files are likely a very good indicator of what you can expect.
