Differential Flow Plot For User Navigation

Before and after a major UX change rolled out across 3 major online mastheads, I thought, it would be interesting to plot the change in readers' navigation behaviour as they browse through different page types. Sankey diagram is good visualization for these kind of problems. However, instead of plotting absolute values, differential numbers (in %) have been used.

By default, Sankey plugin for D3 doesn't support loops or cycles. Luckily, I've found one at http://bl.ocks.org/soxofaan/7c96560677ead0425fe7. You can find my experiments at https://jsfiddle.net/nvy62zt2/2/. A good amount of polishing has been done on Sketch, afterwards.