I'm a mix for both really. It depends on the particular work. For example, Cowboy Bebop. I was first exposed to this with the dubbed, and I can't see myself watching it subbed, because the voices have become part of those characters to me.
But then, with Attack on Titan, I prefer the subbed, because the voices seem to fit better. The english voice actors just sounded...wrong.
As for conveying emphasis in dubbed better than subbed, it's not that hard to hear the emphasis in the original lines, and then just translate that over to the text at the bottom. I mean if the character is saying something with anger, or seduction, or manic humor, it's pretty obvious in the voices, and the words matching up to it reflect that.
So yeah, it's a mix, depending on the work itself.