It's definitely useful , but I'm pretty sure a lot of people here are already familiar with it :)
I almost never use it , for me it's easier to export several jpg images with different exposure from frame buffer and then blend them if necessary :)
Also , if you use Photoshop's Camera Raw Filter, image automatically gets brighter (in 32bit mode). I'm not sure if that's a bug.
Of course, thanks for sharing your tip!