How do you define expressiveness? To me, it means saying more with less. Applied to code it means doing more with less work. Which directly translates to productivity gains.

Now, what IDE and language are you referring too? The best one I've used was VisualStudio for C#. While I'd say typing wasn't adding too much overhead in it, its type system is also poor, and it's arguable that it may not really prevent much bugs. Now, it does help make C# faster.