I've just started reading it, despite having it since it released, and while it seems to have a pretty thin premise, I do like how it's at least making attempts to cover how Lara is coping with the events of the first game. I'm only a few chapters in, and the book seems okay so far.

Edit: 8-11-2015

Holy crap this book is awful. A trite, by the numbers a thriller story, wasting time spelling out full names constantly and minutely detailing things of no importance, only to wrap up is 343 pages with a Deus Ex Machina faux twist in the last few pages.