Yeah - I don't think McCammon was that excited about re-releasing the first four novels he wrote. I got the impression from his blog/interview/somewhere, that he thought the first four were - ummm - crap.
From memory, he thought that he should never have been signed on for his first book and it took four books for him to learn to write a decent book.
I've read the first four and they're not brilliant. But hey - I still enjoyed reading them.