10/10
This movie is a "10" and I´ll explain why:
No over the top acting
No shaky camera
No stupid plot-twists (like one of the cops or another dispatcher being in cahoots with the perp)
Sure, there are moments when you and I will have to suspend disbelief at some of the actions of the protagonists. But considering how they managed to avoid the above mentioned three mistakes, which are ubiquitous in so many movies, this movie deserves a HIGH rating.
(I haven´t actually given it a 10 - I´m just saying ... )