This is a decent anime. Well-crafted (although one does get really tired of The Burst after about almost immediately). The story is unique and the characters, although anime-cliche, well-enough created. Some of the dialog is a little cheesy, but that's not unusual in an anime.
The real problem is toward the ending, where the plot gets somewhat confusing (as in "who is what at this point?") and is both anti-climactic and somewhat predictable. For several episodes it seems to be a repetition of "dodge the Burst kill the Burst evade the Burst shoot the Burst" ad nauseum. Still it tends to remain interesting throughout. The rather weak ending drops this down to an "above mediocre" level, but doesn't place it in my list of "good anime".
They could have had a much stronger, better and more satisfying ending (really, there were no limits to the different endings they could have used), so the somewhat dull choice they made was rather poor writing overall.
Worth a watch perhaps and not "bad anime", but just not up there with the greats.