I am also learning SPARK 2014, a subset of Ada, that is complex, but for me not too complicated. I find Rust complex and complicated, maybe others don't. I will probably stick with SPARK 2014 for my high integrity experiments with hardware and controls. I use C to do a lot of other prototyping and quick apps. My thought is that I will wait for Rust to mature more, but I think it is always going to be complicated and suit the applications it was created for, and I may never have a need for it, or to learn it sufficiently to be able to switch to it.