Well, it really isnt. For me it seems to play very, very safe. Zwick is known for directing action well (The Last Samurai, Blood Diamond); so going in I thought that he would be able to make the elements of the action stand out. While there are moments that do, overall it is really nothing special. Reacher is a character known for having above average skills when it comes to hand to hand combat. While he does use scenes where Reacher literally punches through a car window, he doesn't really go as far as I think he could have. While yes some of it does has to be believable to a point, but you have the ability and leeway to stretch it beyond normal action because that is essentially who the character of Jack Reacher is. While I think the actions scenes are only what makes this film watchable, there could have been a lot more done here.
The main problem I had with the film was the character of Turner. For me, I felt that Smulders did not fit the part at all (and I love her from How I Met Your Mother). While I think she has the ability to be an action star, due to her role in The Avengers, she just seems very out of place and uncomfortable here. There was very little chemistry between her and Cruise; which we were forced into believing in the beginning of the film through a series of phone calls between the two. I found it hard to care for her character because the film glossed over the backstory of who she was. We already know who Reacher is so why not spend some time establishing someone who turns out to be an asset for him? She seemed to deliver the lines very stiff and forced that it was hard not to be distracted by it. If the writers had given more time to delve into her backstory, than I think he character would have been a lot stronger and effective.
One other aspect that I think sounds good on paper but does not transition over well to the screen is the character of Samantha. (SPOILERS TO FOLLOW) Samantha turns out to might actually be Reacher’s daughter. I like the idea of Reacher having someone that he has to care for, when throughout really his whole life he has been a loner. This is a good concept to bring in because it allows the audience to see a different side of him that we haven't seen essentially at all. He becomes more caring and compassionate. While that all seems fine to talk about, the transition to screen does not really work. While I do think that Yarosh had more chemistry with Cruise than Smulders, her character proves to be the typical trope of someone that gets in the way at the most costly of times. There really isn't all of a need for her character once she is introduced and as we follow her further throughout the film, she seems to only be there as an escape. While she ultimately becomes a part of the climactic moment, once that point came I really didn't care much for what was going on anymore.
Bottom Line: The second installment for Jack Reacher doesn’t really compare to its predecessor.