Some of the most practical CHDK features mentioned were:

• intervalometer scripts for time-lapse or repeated shooting
• motion detection scripts for capturing fast or unpredictable action
• exposure bracketing, especially in continuous/multi-shot mode
• extended long-exposure support for night photography
• RAW capture, if your camera can handle the slower write times
• optical zoom during video on supported models

The common theme is that CHDK is most useful when it adds capabilities your compact camera didn’t originally offer. Scripting is a big part of that: even simple built-in or community scripts like intervalometer and motion detection can make a point-and-shoot much more flexible.

One caveat from users: RAW can slow some compact cameras dramatically because of limited processing speed and buffer/memory performance, so it’s useful but not always practical for fast shooting.

If you’re deciding where to start, intervalometer, motion detection, and bracketing are the most broadly useful features for real-world shooting.