6D + Canon 50/1.8 or D600 + Nikon 50/1.8? Help me decide.

I have and use both the Nikon 50 1.8D and the Canon 50 1.8 EF. I use both on crop sensor bodies. For my samples the Canon is sharper with better contrast and the Nikon is better built but is somewhat flat with a slight yellow tint. My Nikon is an older lens made in Japan so time may have impacted the image quality of the lens. I believe the new AFS Nikon 50 1.8 would be better than either of the lenses I have but I have no first hand experience with it.

With all of the apparent QC issues with the D600 I would wait until the issues are settled before even thinking about buying one. If parts really are grinding together as some claim causing the particles that can't be a good thing. If people see that much oil on the sensor what about inside where they can not see?

I am ambivalent about the Canon 6D and think it will probably drop in price shortly. Unless I really really HAD to have a new camera I would wait a few months until all the dust settles