First thing I noticed (critically) about the defense, is the failure of the D-Line to line up fast enough. Probably not a huge concern since it's preseason and the Pats run a hurry up, but it's something I'll be keeping an eye on in the regular season.
Secondly, I'm not too concerned about the running game. Rob Sims looked like he was the weak link last night, but there were some holes that Bush either didn't see, or didn't trust would be there. Consistency is the main issue. That will just take time, and time will help the trap game, which needs work. Another note, Reggie's burst is absolutely ridiculous.
Thirdly, Stafford is still making a decision before the snap, in regards to who he's throwing to, as evidenced by his bad pass to Pettigrew on their first drive.
On Special Teams, the coverage units need to break down earlier. They're overrunning the returner.
I know I'm not the only one who thinks Fairley is poised to have an all-pro season. I think he's looked significantly better than Suh so far. It's going to be awesome watching Suh work with Fairley commanding all the double teams. He does need to line up off the ball a little more. He was all over the neutral zone.
Corners have to work on their line of scrimmage defense. They continue to get beat off the ball. They've got to make contact with their receiver, especially on blitzes.
One thing that would help the defense in regards to penalties is playing to the whistle, not through it. Too many late hit penalties, and that's been a coaching point of Schwartz's that I am not a fan of. He has his players play through the whistle, but you leave that late hit discretion to the referees unnecessarily.
I wonder what's up with Montell Owens' knee. It didn't seem to buckle, which normally happens on an ACL/MCL injury. Hopefully he's ok.