I prefer Odin to Zig after trying both... but it seems Odin's performance is a bit lower than Zig, C and Rust?! Have you noticed any performance issues or it's not something to worry about?

No, I write Odin for production and there is no performance difference to speak of coming from the way the compiler or language works. If you have one it's likely because of an older/different LLVM version being used, but AFAIK Odin stays as up-to-date as you can without tearing your hair out (and that's good because GingerBill has none of that to spare).

There might be a few pathological code paths in the core libraries or whatever for certain things that aren't what they should be, but in terms of the raw language you're in the land of C as much as with any of these languages; Odin really doesn't do much on top of C, and what it's doing is identifiable and can be opted out of; if you find that a function in a hot loop is marginally slower than it ought to be, you can make it contextless, for example, and see whether that makes a difference.

We haven't found (in a product where performance is explicitly a feature, also containing a custom 3D engine on top of that) that the context being passed automatically in Odin is of much concern performance-wise.

Out of the languages mentioned Rust is the one I've seen in benchmarks be routinely marginally slower, but it's not by a meaningful amount.