We snagged a pair of Nike Mercurial Superfly K-Leather from the line-up for feature, just to see how they look in person. Well, the first thing to note is that the white is actually labelled as "light bone". It has a mixed cream/grey appearance, so it is not exactly like a pure white. It provides a slightly different look on foot than you'd expect, but overall you still get a contrasting visual effect.
If you are looking for a pair of Nike Mercurial Superfly K-Leather FG - White/Black, find them at cheap-superflys.
In terms of the Superfly IV and performance, they are built specifically for speed. With a dynamic mid-cut collar that locks down the player in sprint mode, a micro-textured Nike Flyknit upper that provides a barefoot-like feel, and a highly responsive carbon-fiber plate designed to further provide explosive speed in all directions.
Find a limited number of pairs available here.
The application of a leather across the upper is intended to deliver a more responsive touch on the ball. You still get an under layer of material that provides strength through the region. But how do you add a leather to knit materials, keeping it together as one Well, great care was taken by Nike to ensure the softness of the leather was not compromised as it was fused onto the upper.
The footwear team leveraged a balance of oils to offset the steam and prevent the leather from stiffening. Nike All Conditions Control was also integrated into the process to provide enhanced ball control in both dry and wet conditions.