I used to do a lot with AutoLisp in AutoCAD back when it ran in DOS. Did a lot of dynamic creation and manipulation of the models with it. It was useful and a lot of fun (aside from parenthesis nesting).
I did that back in the 90s too. A modern IDE like set of features for lisp would've been awesome. Notepad on NT4 didn't cut it :)
I use a scheme variant in an optics simulation product.
It's actually very pleasing to work with. I wish there was more stuff like this. Lispy programming languages and CAD seems like a natural fit.
That said, python is preferable for most people.