Sharpness is not everything.(for sure 50L is not lack of capable here )
The magic about this glass is how it handles harsh light condition,how it renders the colors in such a amazing tone and the elegant gradation of DOF.That combines a impression of a photography.Never a audience will praise your work because it is razor sharp,especially girls your shot
.Solely struggling on sharpness is really childish for any photographer other than equipment fan.
Just treat it like a price-smart version of Noctilux.