I've used both to work on a hobby OS project (Nim[1], Zig[2]). I very much prefer Nim. Code is succinct, elegant, and lets you focus on your core logic rather than fighting the language.
Zig is nice and I like its optionals support and error handling approach. But I was put off by its noisy syntax, e.g. !?[]u8 to represent an error union of an optional pointer to a many-pointer of uint8. Also having to prepare and weave allocators throughout most of the code that needs to dynamically allocate (which is most of the code) gets in the way of the main logic. Even little things like string concatenation or formatting becomes a chore. Zig also doesn't have dynamic dispatch, which makes polymorphic code hard to write; you have to work around it through some form of duck typing. In the end I realized that Zig is not for me.
Zig is nice and I like its optionals support and error handling approach. But I was put off by its noisy syntax, e.g. !?[]u8 to represent an error union of an optional pointer to a many-pointer of uint8. Also having to prepare and weave allocators throughout most of the code that needs to dynamically allocate (which is most of the code) gets in the way of the main logic. Even little things like string concatenation or formatting becomes a chore. Zig also doesn't have dynamic dispatch, which makes polymorphic code hard to write; you have to work around it through some form of duck typing. In the end I realized that Zig is not for me.
[1] https://github.com/khaledh/axiom [2] https://github.com/khaledh/axiom-zig