Dean Koontz isn't the craftsman Stephen King is. His stories are exciting, but he doesn't provide the emotional impact you get from Stephen King, even at his best.
I went through a phase where I couldn't get enough Koontz, but I've gone off him recently. I thought Strangers was great, and so was Lightning and Whispers. I also liked Twilight Eyes. I didn't like Watchers at all, because the middle third was boring as sh*t.
I recently read The Taking which for 90% of the book was excellent, but the end was very disappointing. I don't want to spoil it for anyone though, but I was very disappointed.