The three things that stand out to me is
1) 87's body language is way better
2) defenders are way, way, way more hesitant about playing the puck carrier with their stick and don't touch any player away from the puck at all, ever
3) the team without the puck is closing gaps much slower than they get closed now.
Regarding #3, whether coaches are coaching more pressure or guys just cover more ground, I don't know, but I'd be interested in how many players from that season are still active, even though it was only four years ago. I can't imagine more than 5 or 6 on that Thrashers club are.
Edit: fourth thing I'm noticing. With 2-3 players high on the PP and 2 more deep, we had way more ice with the man-advantage and clears were harder to come by for the other team. Also, 87 is not on the right half wall, ever.