I don't get the hate for this game. It easily tops the original and Ace Combat 6 structure/plot-wise.
The game is better than its predecessor in every possible way. Only "downgrade" I noticed is how your plane is forcefully selected during campaign. Though it may be a good thing for some because that relatively adds a level of challenge to missions. The difficulty overall has been increased considerably since its predecessor, especially during the later parts of the game. Add to this fact that the plot uses actual real-life locales and a few non-flying missions to add variety and you got yourself a solid arcade flight simulator. The presentation has also been touched up.
Overall, this is a solid follow-up to the original and one that Arcade Flight fans shouldn't miss. Don't believe the negative hype and try this game out if you get the chance.