I’ve always been interested in how PySAL stacks up with NetworkX for building the dual graph of polygonal lattices, so I did some perftesting. This is by far the most common spatial operation I do on a day to day basis, and it looks like PySAL’s constructors still are the fastest for cases where we can assume planarity. But, with how simple the geopandas-only solution is, I look foward to the day when the geopandas.sindex code is sufficient.