I agree with your subject line, OP. It always seems to me that Malik Davis gets discounted or dismissed by lots of people. But each time I see him play, whether preseason or regular season, he's consistently getting 4, 5, 6 yards a run.
He's got decent size and athleticism but doesn't necessarily blow you away in either category. But he seems to have good vision and quick, sharp processing. He often finds the hole or crease quickly and gets north/south right away, while making the right cut at the right time past the first level. Not an elite back, but a steady one.