This seems like another "better vibes" release. With the number of benchmarks exploding, random luck means you can almost always find a couple showing what you want to show. I didn't see much concrete evidence this was noticeably better than 5.1 (or even 5.0).

Being a point release though I guess that's fair. I suspect there is also some decent optimizations on the backend that make it cheaper and faster for OpenAI to run, and those are the real reasons they want us to use it.