The moment you get your hands on the 1DX it feels and looks imppressive, you will notice its weight straight away. I prefer it to be this way rather than light, the 1DX really sits rock steady in your hands.
Moving around the camera I was first drawn to the memory card opening, and the battery release.
The battery is about twice the size of the 5DmkII sliding in nicely from the left side. The memory cards are accessed from the back of the camera. The dual CF slots face backwards at you rather than at the side, I prefer it this way too, keeps the camera facing forward ready to go again.
The menu layout is very similar to the 6D which I got my hands on last year, straight away it feels simple to use, it all makes sense.
Going through the menu options is something I encourage any camera user to do, get to know your gear inside out.
Checking through the menus one of the display features that can cause a lot of problems to my workshop attendees has been taken out on the 1DX, this was nice to see.
I like the toggle button being in two locations, great for when shooting portrait.
I liked the options for saving the files, being able to select dual saving i.e. to card A and card B, or to save to one card then to goto card B when card A is full, or save RAW to one and JPEG to the other, great feature for reviewing your JPEG files quickly after an event.
More to come on the 1DX soon.