Reading Killing Floor felt like watching an old movie narrated by Tom Selleck -- if Tom Selleck were a killing machine. The ULTRA-uber-cool protagonist tells you the story. In short sentences. He's efficient, calculating and has no time for that pesky little thing called 'emotion' which just gets you killed. Oh, and he scores a hot chick.
The plot was quite clever/interesting -- but Child's idea (the 'key' to it all) has been used since, in at least one movie, so instead of feeling stunned ('brilliant! everything just fell into place!') I felt 'ah, yes, I've heard of that.') That's not Child's fault!
If you like action movies with an exagerated hero who violently kicks butt and gets the girl (at least for now), then this book is right up your alley. If you're looking for a little more depth... rather choose another book.