Thanks for the nice review. You talk about "developer productivity" in a number of places and some of it jumps out to me as potentially problematic. If we only consider writing the first draft of code as being the bar for productivity then the way you use it seems to fit, but it seems to me that real productivity with a language needs to include debugging, refactoring, and maintenance. You describe scripting languages as being being good for developer productivity, but my experience is that this is only true when you are dealing with scripts. When a project grows, ages, and has multiple developers touch it, the more a compiler can do to show that things are correct, the more productive those developers will be. For this reason, it seems to me that Rust has the potential to be extremely productive for large projects when the full development process is taking into account.