I'd be interested to know where you heard that Rust was enabling GC again, because that's never been the case. The plan for quite a while now has been to move the machinery for garbage-collected pointers out of the language itself and into a library. In the bleeding-edge version of Rust, it's already the case that you have to explicitly opt-in to using the old built-in managed pointer scheme.

As for your side note, I just want to point out something: Rust's two remaining built-in pointers (owned pointers (~) and borrowed references (&)) are raw pointers at runtime. There's no dynamic overhead, all their magic happens at compile-time.