James Walker and the rest of the NFL media is ALWAYS going to be bias against the Dolphins.
What he fails to talk about is that the Dolphins defense gave up a lot of their points off turnovers. The only knock I have on the Dolphins defense is making more plays (sacks, INT's, fumbles, tackles for loss, etc). With Coyles as the new DC, we're definitely going to be seeing more playmakers.
Adding Mario Williams to a defense doesn't automatically make them better than other defenses. The Jets are overrated on all accounts. I would put the Dolphins as the top defense. And I think the Pats D will improve greatly .