You'll likely get tasked with fighting a fiend or two if you travel through Syrania, as tribute for being permitted to interact with the Angels who inhabit the plane.  (The typical procedure for traveling between coterminous locations rapidly is to make an alliance with the inhabitants of the plane for safe passage, then do something in the city coterminous to your destination plane so they'll open up the portal.  A lot of people refuse or fail, and are thus held prisoner in the plane.)