- The files are smaller and don’t clog up your hard disk.
- The quality is just as good as RAW or so close it doesn't make a difference in the real world.
- Saves time as there is no RAW post processing to be done.
- RAW gives you all the options to tweak your images to your heart’s content, while jpegs lock you into the processing decisions programmed in by your camera manufacturer.
- You can easily correct white balance mistakes.
- You can retrieve more detail, particularly out of highlights.
- The quality of the final image is superior to a straight jpeg.
- If individual colours need to be finely tuned for a colour critical fashion, product or reproduction shot.
- In a very high contrast scene where you’re trying to retrieve every miniscule detail out of shadows and highlights, and your shots will be printed extremely large.
- You want to heavily manipulate your image and need to reduce the risk of blowing out colours.
UPDATE: March 2012 - I never did quite transition to shooting mostly JPEG. Although I know that JPEG will deliver great results the added 'safety net' of shooting in RAW and the potential to adapt images in the digital darkroom, together with a slick workflow have kept me shooting RAW.
This blog post remains valid as each photographer should continually challenge their assumptions and the way they work. This is the only way to progress.