My issue is that I would like types for when I get data from the server, but I don't really want to deal with casting window to "any".

I personally went through the pains of learning javascript and have come out on the other side comfortable with its dynamic types. I really like the idea of compile time error checking, but I'm not sure I would stand for adding the complexity of generics.

The change in my workflow is not very difficult. For example, when I'm using plain old javascript, I use documentation to find out how to use third party libraries and DOM manipulations. Though it works out for all of my needs, I wouldn't mind adding types. Adding types on top of that would reduce casting and spelling mistakes, but it's not like I can't open up the browser and test my code with a step through debugger. I would personally prefer opening the browser and maintaining readability in my code versus having type safety in my code and giving up readability.