“That being said, the answer to my question above is a very definite “no, I am more productive without it”.”
The picom maintainer had a year of free Copilot and found it good for boilerplate and useless for anything unique to his X11 compositor. Each suggestion took 2 to 3 seconds, against clangd’s instant ones. Worse, he never learned to predict when it would spit out gibberish. GitHub gave him a year free to get him hooked, and he won’t pay for it.