I did the comparison when I bought the 7D II. For the last year I have been shooting RAW + JPG because of all the wasted time converting average family pictures for such a small benefit. Properly exposed, decent ISO with the right WB the amount of improvement you can get is really minimal. This was less so with the older bodies like the 7D and 5D II. Both of those bodies had more head room for pp than the new models. I think Canon's firmware has gotten better and we get better files out of the camera because of it.