UPDATE Oct 2013: Man I just didn't realize how much information would be missing since this doesn't cover the diesels. I'm just trying to locate information for typical service. No such luck if you've the diesel. I knew this, but realizing it is worse than I thought it'd be.
Original REVIEW: I prefer Haynes over Chiltons because they talk to me like I'm an idiot. I prefer Chiltons over Haynes because they don't treat me like I'm an idiot. Huh?
Chiltons is geared towards the pro. Haynes towards the novice. Or, like me, the reluctant backyard mechanic. I don't really enjoy working on cars anymore. Haynes will give alot of useless information, but there's alot of important details in there too. Sure you could just look it up on line and I usually do. But when you're right there under the hood you can have the book open next to you. For about $18, yea, I'll do that. I especially like the torque numbers they list. Awesome for a guy that likes to snap bolts.
As for Chiltons, a bit over my head. Haynes is a bit under my head. But since cars are no longer designed with the backyard mechanic in mind I figure that if Haynes doesn't cover it then I probably shouldn't be doing it (based upon my abilities).
I suggest for anyone that does anything more than oil and lube to pick up a Haynes for any vehicles say 4 or more years old. If you're without a laptop you can place outside then you'll be glad you've got the info right there with you when you need to work on it.