I love this book!
I found the story really good, and it has loads of action!
The relationship between Riley and McClane was particularly interesting, especially in the beginning when they were starting to get to know each other.
Was some of it slightly unrealistic? Maybe.
Do I care? Hell no!
Who watches action movies for the realistic plot? Exactly.
So why does an action book need to be perfectly realistic? It doesn't (in my opinion).
Just read it! It's pretty darn great :)