I'm not a Rust-only developer, but a general systems programmer, and my foray into embedded is limited to a side project (see my profile), but no, I haven't switched to C/C++. Rust brings too much goodness to give it up.

Rust-embedded is an easy ecosystem to work with (if immature), and if you want more flexibility, Tock OS [0] is trying to cover that space (also immature, but I'm working on it).

[0] https://www.tockos.org/