got one. yea i have to say the contrast is alrite/a bit lacking. nothing a bit of photoshop couldnt handle.
i dont know why you would want to go from a f1.8 to a 2.8. i say if youre not in want of the macro function, get the 1.4. youll miss the extra light. i bought this lens to cover the 50mm range + give me a macro to use. a money saver? maybe hehe
autofocus on this thing sometimes pisses me off too. if you pick an area of flat color/smooth area wide open, it frequently hunts forever. im not sure if its supposed to be like this or maybe i got a bad copy. but as fStopJojo said, this thing is very sharp, as with almost all macro lenses
but at the price i got this at, it was a complete steal so i cant complain =)