I just played a game with HDR on and it looks very nice, but... When it was really bright out it was too bright, almost to the point that it almost heart my eyes to look at my screen. There needs to be a way to calibrate the brightness of HDR.
the shaders need fixing, they all work but some are incompatible, and depending on the system your using some shaders don't compile. The luminance post processing effect one is the one that brightens the screen dynamically. Look at the log files here. C:\Users\"yourusername"\AppData\Local\Uber Entertainment\Planetary Annihilation\log. have a look at my log file, you will see that the luminance shader isn't compiling. its due to some shaders using 1.1 standards and others using 1.3 standards, some shaders have no version label so are defaulting to 1.1 version and the code is incompatible and it wont compile.
hopefully one of the dev's will go through and fix all the shaders making them all use the 1.3 standard. and will remove the dependancy for GL_EXT_gpu_shader4 which from what i've heard is obsolete and not supported by many cards.