Really the only flaw is the incomplete rosters. It's not EA's fault. The game changed so much over the summer. While it has the new rules, you have no Crosby (Pittsburg), no Vanek (Buffalo), no Ovechkin (Washington). No rookies period. That is I'm sure a let down, since all three of the mentioned have contributed quite a bit to their teams, but like I said, you really can't be mad at EA.
Some people complain that EA's NHL games are too high scoring. You can tell those people to get off of beginner mode. Tell them to play a mode that challenges them if they are dissatisfied.
I have mixed feelings about the new features
Sim Intervention: This is my new best friend. You can simulate parts of games. Meaning that if you are loosing, you can pop in at any time and score a few yourself. And you don't sit and watch the whole game either, about every five seconds a period is over. On top of that if you come back to win it, you get bonus upgrade money (normaly you get $20,000 for winning a game, but with sim intervention, you can get much more, depending how far behind you were when you started playing. I've gotten over $50,000.)
Hitting: This isn't a new feature, but it's nowhere near as good as the previous games. (I'm not sure if they changed hitting power in 2005, I didn't play that one.) Even when you turn up hitting power, it still sucks.
Free 4 All: To multiplayer games, I didn't really enjoy either of them.
My only other beef about this game is that when you draft rookies in dynasty, you need to sign them, whereas in 2004, you could just let them go to free agency. So if you don't want them, you need to sign them, and then drop them, and it's just a pain.
Overall, I've lost a lot of sleep. That's the sign for a good game.