I hate to say it ... but after 18 books, Reacher is starting to suffer from the Spenser Syndrome: a great character that is becoming redundant.
Robert B. Parker's Spenser novels were phenomenal books until about #14 ... then trouble seeps in. And the more Spenser's main squeeze, Susan Silverman, is involved in the story, the worse it is.
Same with Child. Reacher is one of the most interesting characters but over the last few novels, (particularly with the recent stand-alone short e-books) Child has seemed to be grasping. When you start going back to the character's childhood, things are starting to jump the shark. It's the TV sit-com rule ... introduce a baby when you've run out of ideas.
The storyline of "Never Go Back" pushes incredulity (even for a Reacher book), and the final dissolution of the plot is ... well, lame. They even introduce a baby - a sub-plot about Reacher having father a child 14 years before - that is hard to believe, particularly when the 14-year old kid acts like a 35 year old war veteran.
Here's hoping that in his next book Reacher runs into Susan Silverman, kills her and Spenser and Hawk vow revenge. The three have a showdown in which all of them die.