>The price difference between the two is quite significant. That, and there is a HUGE reason why >professionals industry wide use the FX sensor, for that "special" ingredient. Have you any evidence? In the UK I see more Nikon and Canon pros use crop sensors as well as 24x36 than use only 24x36 - presumably because each format is best for some photographic tasks - and pros tend to try to use the best tool for the task in hand
Photography is a bit like archery. A technically better camera, lens or arrow may not hit the target as often as it could if the photographer or archer does not practice enough.