I don't have a Zuiko 50mm f1.4, but I do have the Zuiko 50mm f2.0 macro, 50mm F3.5 macro, and multiple Zuiko 50mm f1.8 (including the silver nose, later MC Japan version, and last MIJ version). All are very fine lenses in their own way.
That said, I do think the 50mm f2.0 is the best of all of the 50mm lenses I have. It is very sharp (as are most of my other 50mm Zuikos). But what sets it apart is that it clearly has the most pleasing rendering and the smoothest, creamiest and best bokeh by some margin. It is excellent as both a macro lens and as a general purpose normal lens. I believe the Mike Johnston, editor of Photo Techniques has written that he thinks the 50mm f2.0 macro is perhaps the very best normal lens out there at any price (and he claims to have used almost everything including the Leica Summicron).
The biggest drawback of the lens is clearly the price, typically being in the $500-$700 range. Having such an expensive and not too readily replaceable lens does make one reluctant to take it out in adverse conditions (rain, beach, etc.) where one could get some really nice photos. The next biggest drawback is the lens is a bit chunky and will obstruct mounting an OM camera (without winder or motor drive) onto some larger tripod head disks. While I don't consider this a drawback, as mentioned above the 50 f2.0 does have a very long focus throw which appears intended to permit critical focusing adjustments for macro photography.