Everything is nigh-on perfect bar the looping.
Totally awesome tune!
One major gripe that completely ruins it imo - the disparity in volume between end/start sorta gets annoying when it loops.
Other than that, it's seriously awesome - the hard beats, the sirens, the amount variation whilst you keep that constant tempo and aggressive beat... it's just a shame about that slight issue of the start.
Have the beats at the start and make sure everything else matches up as well, then it'd be nigh on perfect.