No, that's not the best. https://github.com/rust-lang/rust-mode is.
There's also https://github.com/phildawes/racer (haven't tried it myself, I've yet to get into Rust).
I use Racer with Sublime Text 3, it works pretty well!
works great with emacs.
Re:Visual Rust 0.1 is out
by steveklabnik on Thursday May 14, 2015 @04:57PM
(#9547538)
We have an official one in the rust-lang org.
Not bad.
[1] https://github.com/toshok/rust-mode