I went out today and I had a D750 and an X-T1 with me. I wasn't really planning to compare them but it happened I took a shot with both of the same subject.
Perspective is slightly different, DOF is slightly different also and so is the post processing (used the Fuji Velvia as a start vs Nikon Standard).
The X-T1 with the 10-14 @ 18mm, F8, ISO 1600, 1/60; the Nikon with the 24-120 @ 52mm, F8, ISO 1600, 1/60. Both handheld.
I don't know what the 18 is for the 10-24 but on the 24-120 the 52 should be close to peak performance.
All these being said, I'll let the images speak in regards to sharpness. I didn't think it's funny just having bought the D750 recently.
PS. in the comparison, the Fuji is the left one