Years ago, the question was always posed the other way around. "I'm running OSPF. Why in the heck would I wanna run IS-IS" ? As if OSPF is the logical choice, and IS-IS was only for hipsters.
Good to see it's the other way around these days. 🙂
(I'm an IS-IS fanboy myself. Even though I've worked both on an IS-IS and an OSPF implementation. Or maybe: *because* I've worked on both. 🙂)