If you watch this movie trying to critique it and look for plot holes, you'll find yourself rewarded, and not enjoy the movie. If you just want an action movie, fight scenes and lots of guns going off, with a decent plot and acting, you'll also find yourself rewarded.
For me I enjoyed it. I actually liked Mark's character, the plot twist and the actions. My only regret was letting critic's reviews deter me from watching it at the theater.