The ownership idioms are very similar to idiomatic C++11 and std::unique_ptr. Which is to say that Rush has got an industrial strength safe memory management system.
But Rust stands out because the rest of the language is such a joy to use, compared to pretty much any other 'systems' language out there.
One of the cool things about the Rust ownership system is the lease/borrow system. Moving is cool, but much of the time you want to synchronously call another piece of code and give it a temporary (stack-frame-long) lease for that pointer.
Rust starts with ownership, but makes it easy to ergonomically and safely lend out that ownership (including one-at-a-time mutable leases) of both stack and heap allocated pointers.
I've been programming with Rust since last December, and I have had essentially zero segfaults coming from Rust code during that time frame, roughly equivalent to what I would have expected writing code in a language whose safety guarantees come with a runtime cost (GC or ARC).
But Rust stands out because the rest of the language is such a joy to use, compared to pretty much any other 'systems' language out there.
Congratulations to the team!