If ur looking for a speciffuc vehicle one go to advance auto they have both and you can compare that is what i did for my 1988 f250 diesel . Chilton was better for me because the diesel engine section was better with more pictures.
I have both for my truck. At least on my truck I find the Haynes better, but there are a few things I've gone to the Chiltons to get a better picture or diagram of.
I normally get both if I Know im going to keep the car and need a lot of indepth information. They each have there areas that they focus on more than the other.
For each vehicle I own I've a Chilton and a Haynes. However, the best bet for working on your own vehicle is a Factory Service Manual. Don't leave the dealership without one... or buy one later on Ebay. They've saved my cedar end more than once. They're far better than either Chilton's or Haynes. I often do my own automatic transmission work and the Chilton's or Haynes don't address these unless in a very rudimentary way.