One talk, that was quite interesting, was from a company with 180 developers that did a slow and careful rollout of AI, mainly due to high demand. They did a self-assessment, and developers claimed increased productivity. They said it was too early to say if it was actually true though, and promised to come back with results (presumably another year) if they had any.
It's the same where I work. Developers *feel* more productive, but I have yet to see any numbers backing it up.