3200 on a 5DIII is like 200 on your Rebel body or 400 on my 50D. To add to the conversation I stopped in Costco and took my own SD card so I could shoot a few samples with the 70D on display. I took several at 6400 and 12800 and it was nothing short of amazing as far as noise control and sharpness with the kit especially considering it was the 18-55 kit lens. I'd buy one right now but I didn't like the body size, it's too small. I really like the feel of the 20-50D body sizes and feel right at home using them. Paul