Here are other threads too but this will give you an idea Choronr.
http://forums.planetside.co.uk/index.php?topic=2356.0Basically the light range is much wider as in BMP , Tiff or other 8 bit formats.
Thus you can make much better adjustments without rendering ones more the same image.
The thread is a little old. There are much more programs today that do this kind of adjustments .
HDR uses kind of the same technique .
So i save as BMP and EXR all the time.
When i think i can tweak the image in post it becomes very handy to have the EXR output.
Or you change your mind and change the appearance in a way you didn't intended at first.
It has it limits of course
After you make the changes you want you can save it in any other format you want.