Ok here you go 2 images. One from the FA50mm f1.4 and a 100 %crop and the other from the FA50mm f2.8 and a 100% crop. Both shots are at f2.8
As above, K10D shot in RAW, 2 sec MLU, Tripod ISO 100 Converted in Pentax Browser directly to Jpegs no sharpening. There is one error in the captions. The FA500/1.4 was at 1/1250th and the Macro was at 1/1000 but that doesn't matter for this test. Not sure why but the sky had thin cloud cover and might have darkened slightly between lens changes. The shutter speeds will make no difference in sharpness/bokeh etc tests anyway.
Click on the image to view it in a larger size
Click on the image to view it in a larger size
Click on the image to view it in a larger size
Click on the image to view it in a larger size
You can see that the Macro is a little sharper and the bokeh is a little smoother but that really only shows up in the crops. In real world shooting where you don't crop or do very little (as you should) these 2 lenses are extremely close. But the difference becomes more noticeable as you stop down further. The 1.4 gets sharper but the macro gets even sharper. The OOF areas are nicer in the macro as well but that's to be expected. These lenses are designed for different purposes.
Anyone that chooses not to own the 1.4 based on this is nuts. Forget the "for the money" qualifier. This is a great lens. I have shot with many lenses like the A*85/1.4, 77mm Ltd, 31mm Ltd, 42mm Ltd, 40 & 70mm Ltd, Kiron 105 macro and a number of others. The 50mm macro is as good or better than these lenses, especially for it's intended purpose. The 50/1.4 is so damn close in quality to the macro is just more reason that this lens should be in every serious bag. The fact that it's cheap is just a bonus.
Buy it and don't pixel peep it to death even though it can hold up to that.
Btw, The RAW's are damn fine and these reduced sized Jpegs don't even come close to the quality of the originals.