I have recently been using the “RAW + jpg” setting on my Canon DSLR. It is useful in some circumstances as it gives a jpg image that can be used immediately. If I’m not happy with the jpg or want to do some editing for any reason I use the RAW file. I find I only use the RAW about 10% of the time so it allows me to upload my photos much faster.
There is a couple of drawbacks. First it reduces the number of images that can be taken before the camera stops shooting and gives its busy message while it saves them. This is only an issue when in continuous mode. If shooting single shots it is fine.
The other issue is downloading the images to the computer. I use digiKam for photo management. I always rename the files as I download them from the “image_xxxx” format to something a little more meaningful, normally I use a “date-subject-num” format. When downloading with the default settings digiKam will number the cr2 raw file as 1 and the jpg as 2 etc. However I found a setting in the download options for numbers to use the extensions. This will give the cr2 and jpg the same number with only the extension to differentiate the 2 files. Exactly what I wanted. digiKam continues to amaze me with how powerful and useful it is.