Depends on how often and where you write those keywords. mut seems to be quite common and even in D I would not like 'reference' more than 'ref', especially since it is used in parameter lists.
I think Rust's "pub", "priv" and "fn" are just silly. But I don't mind "mut". However it might've been nicer if you didn't have to write "let mut" but just "mut".
What made Rust a no-go for me was when I tried to write a generic sort. I still can't figure out how to swap two elements in an array ("vector"). The implementation in their std lib for "swap" has an unsafe block... (And I don't want a GC or RC requirement for the array.)