[wlesieutre]

Just did some browser comparisons:

Safari has a fade-in and triggers it immediately, so you do get a pop-up as you move your mouse around. But the fade and delay on closing smooths it out enough that it doesn't flash on and off. I don't love that it pops up instantly when I don't want it to.

Chrome and Firefox feel pretty similar. There's a delay on fade-in and a (longer?) delay on fade-out. Looking at it more closely, I think it does check that the cursor has stopped. Moving left to right across a link won't trigger the popup even if you're over it for a long time. So is it just the fade that makes opening feel slow?

I'm not totally sure whether I'd like it better without the fade. Since I don't see a way to turn it off there's no easy way to find out.