Miami turned the ball over on 1 in 10 possessions, which is good but short of spectacular, but those turnovers cost them only 38.9 points (just over 3 per game). Morris threw interceptions on only 1.67% of passes (fewer than Teddy Bridgewater, David Fales, Johnny Manziel, Marcus Mariotta, Ryan Nassib, and Landry Jones to name a few) while averaging 13.7 yards per completion (more than Teddy Bridgewater, David Fales, Johnny Manziel, Marcus Mariotta, Ryan Nassib, and Landry Jones to name a few).
A quick strike offense is complemented by a defense that gets off the field in a hurry one way or another. That was not the case with Miami. The Miami defense was 120th in plays per possession, 119th in yards per possession and 115th in average time per possession. They allowed "only" 2.4 points per possession because the offense handed them great field position - 74.2 yards from the goal line, 5th best nationally - and they turned over their opponents on 15% of possessions. Otherwise, the Miami defense was pretty useless.
Miami is expecting a better pass rush in 2013. If they could double their sacks/pass from 2.9% to 5.8% (league average) without sacrificing coverage in other areas, that should result in a few more third down stops and shorter drives. That could be huge. The defensive front has added beef, which should help with stopping the run. The good news is they couldn't get much worse.
At a glance, we should have a lot of confidence in the offense. They scored a lot of points in 2012 and most of the same folks are coming back to do it again. But the hype doesn't match reality. Miami was only 46th in points per possession in 2012. They were entirely dependent on big plays and avoiding costly turnovers, both of which are high standard error events (in other words, they can fluctuate a lot from season to season). Otherwise, they were league average or worse.
Most folks see Miami as a borderline top 25 team for 2013. From my perspective, they finished 2012 as a borderline top 50 team. I don't see enough improvement on the defense and too much risk of regression on offense to bump them up 25 spots. In this case, don't be seduced by the explosive offense.