There's a dedicated setup mode on the mode dial, which contains most of the settings you rarely change. Unfortunately, that's where Sigma chose to bury the media format option, making formatting a pain. On the other hand, the dedicated manual focus dial works very well.
While I like the layout and function of the control buttons, the etched labels are impossible to see in any light. You just have to memorize that for the three on the left the top one is AEL, middle is QS (Quick Set), and bottom is Menu, and the two bottom buttons are playback (left) and display (right).
I like the Quick Set display. The first page lets you set flash, ISO, white balance, and metering parameters. Hitting the button again offers up image size and quality, drive modes, and color presets. But navigating these settings can be a trifle annoying. For instance, to set the ISO sensitivity, you cycle through via the Up button. When trying to change from a higher ISO to a lower one, I often accidentally hit Down, which would then change the white balance. Argh.