Is this an ad for Vals AI? Looking at their website, the rankings don't mesh with my observed utility for almost any model outside of fable and astra being good-ish.

Absolutely not. I know Elon retweet them a lot when Grok is good. This is how I discover the company.

I like to follow them and look for benchmark for each LLM release.

Ah gotcha, not on twitter so just hadn't seen them before!