When hovering the mouse cursor over e.g. a stream method, I expect to see the actual inferred type in the doc popup.
I cite the “This is how it worked in Eclipse” reason. Other than that, 9 times out of 10 I get annoyed that i just see <T> instead of <ActualType>, which is what I was looking for.
The same goes for ctrl-clicking such methods, expecting to be taken to the correct implementation for the generic type in question.