* High ISO performance worse than 40D
* Reduced dynamic range in the shadow areas compared to EOS 40D
* Per-pixel detail not as good as on good 10 or 12 megapixel cameras
* High-end lenses required to get the most out of the camera
* Poor white balance performance under artificial light
* Flash must be up for AF assist lamp (although AF is good even in low light)
* Live view not as accurate as on 40D (framing very slightly off-center, in contrast detect AF mode not possible to magnify right out to the extreme corners)