So keep that praise in mind while I tell you that this book sucked. The only thing going for it was McDevitt's healthy experience as an author: the book was mechanically well done with a story line that was (despite the time travelling confusions) always nicely consistent and well paced.
What it lacked was, oh, most of everything else. I read this book two weeks ago, and at the moment I can't remember the MC's name nor that of his time-travelling friend. The characters were simply boring despite the handy dandy time travelling devices they played with. The book was also, surprisingly, almost entirely lacking in plot: three quarters of the book consisted of a hunt for one person or another (the dad, then the friend, then the MC) in various times--but it never felt urgent or exciting at all. Halfway through the book I was still waiting for a real problem to appear, and it never really did.
Curiously, this is not the first time McDevitt tried his hand at a time travel novel. His other one, Ancient Shores, was even worse than this one--a real stinker of a book that was so bad I wondered at the time if McDevitt signed his name on someone else's work.
Stay away from Time Travelers Never Die. But honestly, don't hesitate to pick up anything else with McDevitt's name on it; most of his tales are excellent.