Originally Posted by T-bucket23
Mitchell is good for wiring diagrams but that is about it. I have seen them all and for all around everyday stuff Alldata is the best as far as ease of use and the accuracy of the info. The all lack on the foreign cars, especially wiring.
AllData uses the current path style wiring diagrams. If you go to a dealer this is the type of diagrams you would get. I love this style wiring diagram, but it doesn't show the entire circuit. The diagram will only show the current path and not all of the splices.
Mitchell uses the engineering style wiring diagram that is common in most repair manuals. The benefit of this is that the entire circuit and related components are shown. Every splice and connector(almost) is displayed. These diagrams can be confusing, but very helpful. Furthermore, most wiring diagrams in mitchell ondemand are interactive. They use the svgviewer add on to make the diagrams easier to use. You can highlight certain circuits and remove all others from the diagram. I really enjoy this feature of mitchell.
AllData has the best information in relation to bodywork. Unfortunately, like others have said alldata has changed format and the information is very difficult to look up now.
Mitchell ondemand offers tech tips. Right in the repair manual all technicians/consumers can leave tidbits of information. For example if I lookup a repair procedure for a steering rack replacement on a Passat VW. In the repair information there are tech helps posted. Sometimes these tips are helpful and are a benefit. For example you might find a tip on how to locate a common splice or ground.
I currently use ALLDATA Collision and Mitchell Ondemand. Customer service from ALLDATA is by far the best. Both resources are online. ALLDATA offers on demand information requests. Fill out a simple form and submit it. ALLDATA will respond with the information as quickly as possible. I use this feature for the Big Trucks wiring diagrams and vintage wiring diagrams. Mitchell ondemand also has some vintage wiring diagrams and information request. However, I have had little success with their information request.
Both repair sources get their information directly from the manufacturers. Therefore any limitation in information is soley the manufacturers fault. That is why most foreign information is lacking. However, ALLDATA simply imports the information into their format. Mitchell interprets their information and changes the structure/hierarchy. The repair information and wiring diagrams are interpreted. They take the factory wiring diagrams and transform them into their interactive engineering style. This can be detrimental since people do make mistakes. When the information is processed by mitchell it has a higher potential to be incorrectly entered.