I'm not a fan of traditional barbell rows. I know, Lee Haney and Ronnie Coleman liked them and their backs were huge. Well, their backs would've grown even if all they did was paint their toenails.
One tweak that can make a barbell row better, though, is using a cambered bar. This allows for a greater range of motion in the contracted position as your elbows can travel back much farther.
The camber in the bar allows for an extended range at the top. However, you can't get an extreme stretch at the bottom.
By getting your elbows up high you get a solid contraction at the top. Also, adding a few chains enhances it, as the weight is heavier in the contracted position.