I'm using both a lot. Rust has better compile times than Swift. It is especially not prone to these "one expression takes 60 seconds" scenarios. Although I feel that things have improved considerably with Xcode 13 beta. On the Rust side, there's an (almost-done) alternative compiler backend called Cranelift that brings 30-50% faster compile times for debug builds. This improves the iteration time considerably.

https://news.ycombinator.com/item?id=25130528