When I went digital, I opt for Fuji and bought Nikon glass. I upgraded my system to FX Nikons over the year. I had great Nikon glass: 14-24, 135/2.0, 85/1.4 and some good Sigma's.
That said, I was blown away with Zeiss, the simple Planar (85/1.4) did it. The rendering, the handling, the feeling of the image made me choose more of Zeiss and in the end I sold all my Nikkors.
At the other hand, I also love the look of DP3m, a sigma.
I guess every lens has it's character and it is up to us to get the best out of it.