I learned from a Canon Live Learning instructor that it is a good idea to first open a RAW file using DPP, and then saving it in a lossless format (for example TIFF) and then continuiing in the editing workflow with the file that was saved. This is because DPP understands data specific to Canon equipment that third party software may not fully understand. Thus they recommend not opening the RAW file directly in a third party program.
My work is not too detailed, so I may not fully appreciate all the differences, but certainly there are some items like the focus points that DPP shows, that other software is unable to show, so that is useful for me.
