In addition to the traditional PASM
exposure modes, Pentax offers a Sensitivity-Priority option (Sv), which automatically adjusts shutter speed and aperture as you scroll through a user-determined range of ISO sensitivity values. It's a nice alternative to the trial-and-error approach to finding the lowest ISO sensitivity that will deliver a desired exposure.
You can program the green button to reset the camera, choose the image settings, show a depth-of-field preview in the viewfinder, apply an effects filter, and reset the autofocus point to center or override the file format settings. I really like Pentax's file override capabilities: you can define a behavior for any given scenario.