Burst is such an interesting project. The fact that, because they know what they are trying to do more than a c++ compiler really can due to the intended use cases, they can be more aggressive with optimizations like SIMD. I remember a talk where they were discussing replacing c++ code with the Burst stuff as you mentioned, and I recall the biggest reason being they could write more succinct code that kept the speed because they weren't having to convince the compiler to do a lot of optimizations they needed to keep it fast.