I bought this approximately 1 week ago as I was becoming slightly disillusioned with my previous Canon, an EOS 5D. The 5D was capable of really beautiful images but I've become really in need of a much more rugged camera which can shoot at high rates and also I was getting sick of vignetting on wide angle lenses and dust on the sensor.
I figured if I really need wide angle images I'll just use my Hasselblad film camera, which for me still knocks the hell out of digital and I wanted a rugged camera for travelling around China, where I am at the moment. Luckily my order came through the day before departing and after taking around 3000 shots so far all I can say is the camera is way way better than the 5D. Images are so noise free, I've shot from ISO 100 to 1600 and the noise at 1600 is similar to 200/320 on my 5D... astonishing.
The speed is incredible, autofocus is absolutely amazing, metering nigh on perfect each time and it feels correct in my hand. Ergonomics are superb and in my opinion the menu system is much easier than the mk2 generation of EOS 1 cameras and if anything much more logical than the 5D.
Can't recommend this enough. If you want the best in 35mm digital technology, this is right now the best by far. Just looking forward to checking out the 1DS mk3.