I put Fujifilm lenses into Good, Great and Exceptional categories (there are no optically bad ones!), IMO the 50-140 is great (bordering on exceptional), the 90mm is though exceptional! If you need the zoom take the 50-140 if you want the ultimate then take the 90mm.
The 90mm isn't just about sharpness, its about colour rendition, the way the bokeh is handled at F2/F2.8, the way the subject pops, it has a way of making portraits just look beautiful. its just one of those 'halo' lenses that in years to come will be revered (like the Canon 135F2, and Zeiss 50mm Planar). You need to use one in anger to 'get it'
I'm off to a wedding today, as a guest, and I know the 90mm will be welded to my camera.