After reading: I find the Webkit arguments generally more convincing than Chrome's. I'd love to see more 'hybrid' layouts built from existing properties, & I'm skeptical about 'auto'-size masonry tracks. But I also know Chrome is working on a prototype, which will be interesting to see.

I also found the hybrid layouts argument the most compelling.

I think Microsoft is working on the prototype

I seriously don't understand the auto argument. At worst, it means in some scenarios you'll want to specify your tracks instead of using the default, and like, ok? You'll do that in either? It feels like it's trying to argue against 'auto' tracks in general, accidentally.