skoal said:
... I see lots of posts here and else where saying this version is bad because of black-crush or white-blow-outs, and that makes no sense.
It's simple math ..
CRUSH or BLOWOUT equals DAMAGE
.. and this is why:

In this shot from 2001: A Space Odyssey, you can see that the full spectrum is well within the limits of displayable area -- from above 0 (absolute black) to under 255 (absolute white). Within this range, we can manipulate it without damaging the makeup of the spectrum.
Above, I've moved the Low from it's default of 0 to 12 for absolute black and the High from it's default of 255 to 228 for absolute white. The before (left) and after (right) displays show that this increases the contrast of the original picture. The graph's red-shaded "flat" area indicates where are the absolute black and absolute white areas.
Notice that under the Low and High settings are % values of 0.000. That means 0% of the picture's spectrum is in those flat absolute areas. That means no picture damage has occurred. And that means no matter how we manipulate, as long as we don't cross into those absolute areas, the spectrum can be returned to it's original state. All the picture's detail information is still available for our de-manipulation (if we choose to do so).
However:

Above, I've forced (whether accidentally or deliberately) parts of the spectrum into those flat absolute areas. The after view looks to have more contrast than the previous settings (which may have been what was wanted), but otherwise the picture still seems to be okay. Only it isn't.
Notice that, with the newer Low and High settings, crush and blowout have increased to 5% of the picture, each. The graph shows that the varied detail of those areas of the spectrum have been flatten into the absolute areas. The picture has been damaged and there is no way to undo it -- all the original detail information has been lost.
So, what does all this really mean? It's the same as dripping black or white paint onto dark or light areas of the picture -- no detail, just a solid blob of maximum darkness or maximum lightness. Below, the crush and blowout damage is hi-lited by inverting the damage areas to prove it's really there, even if it's normally hard to see:
TOP - improperly adjusted picture caused crush & blowout damage
MIDDLE - crush damage hi-lited
BOTTOM - blowout damage hi-lited
[note: RGB hi-lites can mix to produce R-G, R-B, G-B, and R-G-B colors]
