My experience was that LLMs performed at Zig and Rust at about the same level? That is: worse than at something like JS or C or Python, but well enough to write code that works. And they only got better since I first tried them.

Intuitively, Rust would perform worse because ownership is a different paradigm, while Zig is far more similar to things like C/C++. But I guess that's canceled out by the disparity in the language resource base.