Just a simple averaging method in Photoshop
Somehow between 8bit jpeg & 10bit/12bit raw image just 2-4 bit difference
When jpg versus raw, raw needs approx. 3 times more of storage volume then jpeg
That means while simply I take 3 jpeg images with 1EV bracketing method, it's dynamic range is totally over 1 shot of raw.
So is raw images really useful? I think it's depends on situation.
Another sample I test in office while my boss isn't here (see below).
PS: My boss is an equipment follower, so she think that usually takes raw + jpg images is the best method, but I think she's an idiot!
Because the company is selling photos...
1 shot of ISO800 jpg
9 shots of ISO800 jpg with +-4EV
100% crop of averaged jpg