I wanted to upgrade from my Canon 1-D Mark III for several reasons:

• Achieve improved low light performance for when I shoot Washington University volleyball in a poorly lit gym without benefit of flash, and
• Move to a full frame camera for my other photography... landscapes and people.

I used it to shoot Wash U. volleyball this afternoon. The controls are pretty much like my other camera and did not take much to get used to. With my Canon 1-D, I would use the 70-200 mm lens at f/2.8 and shoot at ISO 3200 with a fair amount of noise as a result. The shutter speeds were not all that great either. With the Canon-1-Dx, I added the 1.4x TC to the mix thus achieving more reach. Thus I shot at f/4, used an ISO of 6400 AND got great shutter speeds. Much less noise than the previous camera.

Things I was not necessarily looking for when I bought this camera but love:

• 12 frames per second - the increase from 10 on the 1-D Mark III is definitely noticeable,

• 18 MP versus 10 MP on the 1-D Mark III provides more leeway when needing to crop

This is one great camera! I can't wait to try it out at the Forest Park Zoo.