After writing some non-trivial and performance sensitive C/C++ code, you have feeling of how that code behave on the real metal. I have that kind of intuition, for example. I never had to dive to the level of generated ASM, but I can get ~80% of theoretical IPC with just minding what I'm doing in C++ (minimum branching, biasing branches towards a certain side, etc.).
So, I think if you do the same thing with Rust, you'll have that intuition, as well.
I have a friend who writes embedded Rust, and he said it's not as smooth as C, yet. I think Rust has finished the first 90% of its maturing, and has the other 90%.