When I hear those kinds of qualitative comparisons ("something special" and the like), I can't help but wonder whether part of the speaker's reaction is due to inherent bias. Generally, they know that they are viewing an FX image and expect it to look better. So, they attribute a great image's greatness in part to the fact that it was shot on an FX body when that may not actually have had anything to do with it.
I'd love to see a double-blind test where viewers were presented with a large selection of quality prints and were asked to separate them into taken-with-FX and taken-with-DX piles. I bet the results wouldn't much beat random selection.
Of course, in situations where the ISO has to go up to stop motion, FX has a substantial inherent advantage. But your question doesn't include that particular case.