I added some clarifications in the registered forum so I decided to copy them here to, just in case :)

If you dissect the "gamma option" window, you can see it contains three very different type of control.

The top portion of the dialogue box is what I would call a "convenience or helper" section. The most important thing to understand about it is the fact that it has ABSOLUTELY NO INFLUENCE on the rendered image (if you want to verify that, you can create an image, render it with the slider pushed to the minimum, then again with the slider pushed to the maximum, the final image will look exactly the same :)
Does that mean, this portion of the gamma settings dialogue is useless and was added to make the dialogue prettier ? :)
Of course not :) That's what I call "conveniences controls". In this particular case, they allow you to see the colours in the same colour space as your monitor (the gamma you choose)  while still sending colours in linear space to your render engine.
So, what exactly happens ?:

Let's say, you set your the gamma of your monitor to be 2.2 and you check all the check-boxes

• Affect Color Editor: allows you to pick the colour you want, and vue apply an invert-gamma curve to this colour before it sends it to the render engine. If you uncheck this option, then vue will send the exact colour you picked to the render engine and the result will be darker than expected).
• Basically, all four other check-boxes in the top part of the interface behave the same way and have a very similar result. In my opinion, it's best to leave them checked all the time

 The input gamma field: This is what I would call an "information" control. It INFORMS the render engine about the kind of data you send it

• Very important and sometimes confusing at first: when you enter a value of 2.2 in this field, you DON'T tell vue to apply a gamma of 2.2 to the input image, what you do is, you TELL vue "this image HAS a gamma of 2.2, apply a invert-gamma curve to it before you send it to the render engine

The output gamma field: This is a "command" box, here you give vue a command, you tell it to output the picture in a determined colour space (as far as I know, only matters if you save in a limited range file format, if you export exr, hdri, float tiff, it doesn't really matter, the full range of informtion will still be saved

I hope this will help to make a few things easier to understand and again, I'm not a professional and English is not my native language :) This "tutorial" is really only aimed at beginners who might have no clues about Gamma, I know professionals already know all that stuff better than I do :)

I have honestly no idea if all this blabbing will be of interests to anyone, but I hope many people will discover the power this new settings offers. I have seen images in the gallery made by much more talented people than I am "killed" by a bad gamma and the harsh light transitions it produces, so, I guess my post is a bit egoistic, I want to be able to enjoy the full talent of this artists once they start using the tool :)