The menu system, which is colour coded, is reasonably quick to operate. You use the thumbwheel to cycle through the settings and the Set button, which is located inside the wheel, to make your selections. We have no significant complaints about this system, but it's starting to look dated. The newest menu systems on some recent competitors, which are based on four-way controllers, have more consistent command sequences from feature to feature.
You can also program the Set button to allow instant access to image-quality settings, which are otherwise hidden in the menus. Alternately, you can program the button to access the EOS 5D's colour and tone controls, called Picture Styles (more about this in the Features section). These are useful capabilities, but we'd like to see Canon add one more button to the camera's body and let us directly access both features.
Like the EOS 20D, the Canon EOS 5D has a status LCD and a viewfinder display that do not include a constant reading of your current ISO setting, which we consider a must on a camera of this level. Also, the exposure mode dial on the camera's top-left side spins fairly easily and doesn't lock -- we inadvertently changed our exposure mode a couple of times and would like to see a lock on that control. Finally, the PC terminal for triggering studio flashes is hidden behind an unusually stubborn rubber cover, which most studio pros we know will tear off in frustration by the third day of owning the camera.