Anderson has the consistant line and length combo plus pace and the ablity to swing the ball. He is also great in the field. But can't bat.
Johnson doesn't have the consistancy but when he's bowling well, there's few better in the world. Like Andreson he is also excellent in the field. But unlike him, Johnson can bat and bat very well.
The argument about them being miles apart is in my opinion unfair. They are, when you think about it, quite close. Anderson has the consistancy, but Johnson has his batting. Both are top notch fielders, and both (When Johnson's on) are dynamic with the cherry.
Heart over head being an Aussie, I reckon Mitch just shades Anderson!