Finally found a good source of information here on blender.stack about the saturation problem described in my first post. **Its all about the transformation of the value informations given by the rendered scene to the final sRGB display view.**  

*http://blender.stackexchange.com/questions/46825/render-with-a-wider-dynamic-range-in-cycles-to-produce-photorealistic-looking-im*

Im finding this post very useful and wanted to share it here - have a nice day.