For people who do a lot of post production there are good reasons why Canon and Nikon digital SLR’s or Medium Format; or dare I suggest as a Leica fan, a Leica, are the cameras to go for.
Better dynamic range and more importantly 14-bit RAW files are the key. Try editing a 8 bit jpg and you will soon end up with a posterised image if you go to far.
Olympus are not too bad, but Fuji has issues with its X-Trans sensor and Sony have only had 12 bit RAW files, not good enough for many professional photographers.
Well its now all change, the latest Sony is being released with 14 bit RAW and a firmware update is coming to give this ability to some of their older cameras.