It won’t win any awards; the acting is mediocre and the plot is threadbare.
But you don’t need acting chops in an action movie; you only need believable protagonists, and actual Navy SEALs are about as believable as you can get. And since the plot is generally just tacked on anyway, the fact that there’s enough plot to get us from set piece to set piece, and tell a decent story, is enough (my only complaint is that they didn’t do enough to illustrate the passage of time).
The action, though; the action is why we watch, and the action is magnificent. Read the whole Popular Mechanics article for the lowdown on how working with SEALs influenced the filmmaking; it’s worth it.
And go see Act of Valor if you haven’t already!