A very informal analysis of bat and ccat is that ccat (written in Go) has choked on large files multiple times (which resulted in panics), while bat hasn't crashed on me yet. Of course I've only tried bat on two files so far ;)

I'm asking because although I know Rust is likely to be faster than Go, I'm interested in the amount of difference.

You might be interested in Ben Boyter's journey to write a source code line counter:

https://boyter.org/posts/sloc-cloc-code/

https://boyter.org/posts/why-count-lines-of-code/

Thanks, will take a look at those.