I am a die-hard Idea user as many of you probably know.
However currently I am using (mostly) Eclipse due to project constraints.
I did not argue to strongly against having to use Eclipse, because it couldn't hurt to get to deeper knowledge of Eclipse - well in fact it constantly hurts, but that's another story
To get on the topic: Eclipse by default highlights usages of the element that the caret is in (much like Idea's "Highlight Usages in File" does when invoked explicitly.)
When I heard about it I agreed to JetBrain's official opinion that this behaviour is disruptive and should not be implemented.
Now after having used Eclipse a while, I have really grown on that small feature up to the point that I am really missing it when I fire up Idea.
Consciously you learn to ignore the highlights pretty fast, but they seem to help to grasp context and get an overview quickly.
This has been requested as IDEA-4442: http://www.jetbrains.net/jira/browse/IDEA-4442
Any chance to have it reopened?
Should be very easy to implement. Of course there should be an option in the editor settings, which could be off by default.