Is awesome, for dramatic effect. Sorry, I just got a kick out of sloooowly charging a group of hill giants at a speed that made me look just downright intimidating (like a slow motion heroic moment in an action movie), and then turtling up to tank 6 of them at once for a while.
That's all I had to say.
Oh, and SD, combined with improved shield bash, combined with improved trip... Rocks.