Sharpness and IQ-wise, I can't tell the difference.
Primary difference is that the 50mm is weatherproofed and is brighter (shallower DOF as well). Oh yes and there the thing about the 50mm costing more than twice the price of the 35mm...
The 35mm has another advantage, which is 1x image magnification. But to get this, you'll need to be very close to your subject and proper lighting becomes an issue.
The 50mm macro has been critised by some reviewers for its 0.5x image magnification as "not a true macro lens".
The 14-54mm can actually focus at something just 6-7cm away from its front-most lens element! AF motor is quieter too but when turning the zoom ring, there's an annoying squeaky rubber-rubbing sound -at least on mine.