If you are looking for an action anime that seems to draw upon the story lines of many of the great anime of its genre (read: Gurren Lagann), but lacks the expected character development that is expected in any 24 episode series, more than 2 or 3 glimpses of what could be construed as an original plot, a lot of battles cut off in the middle of it, and a lot of panty shots, then this is your show. If you want a solid, at least somewhat original anime that manages to have a good mix of plot, action, and character development, you should stay away.
Apart from the lack of originality that this series exhibits, I would have to say that the two most annoying parts of this series are the completely obvious "twists" in the plots, and the fact that, in the middle of a large battle scene, everything will stop so that protagonists can figure out what the other side is doing, while the bad guys obligingly sit and watch them do such. Yes, this series does manage to have several "twists and turns," but when you can see most of them coming several episodes before they happen, they tend to lose effect.
The other thing that annoyed me most about this series was the sheer stupidity of some of these characters. When the main character managed to figure out someone's power (even though one of their partner's power was to FIGURE OUT WHAT ANYONE'S POWER IS) everybody was so shocked, even though it was obvious. While this character sat there and figured out what that person's power is, or their weakness, or the plan they needed to use, the bad guys just sat there, politely waiting for them to mount a counter attack. This annoyed me beyond anything else in the series.
In total, ignoring my three major grievances, this isn't a terrible series, and, if you're in the mood for a lot of action, this could be a good series for you to see.