It does seem a little incongruous, or unbalanced, but from what I have read, the 50/1.8 II is an extremely sharp lens once it's stopped down a bit.
It won't give you much OOF blur / bokeh, but if all you want is sharp images at a fixed 50mm, then it should be fine.
FWIW, I use the 50/1.4 and I am very pleased with it. It's quite a fast lens, too, by which I mean that although it's "only" an f/1.4, it actually lets more light through wide-open than my old Olympus Zuiko 50mm f/1.2 lens does! I.e. its T-stop rating must be quite good.
The 50/1.4 has more iris blades than the 5 (IIRC) of the f/1.8. so OOF point light sources will look more round (i.e. better) on the 1.4 than the 1.8. On the 1.8, such OOF blobs are rendered as pentagons, pretty much.