I have both and I think they compliment each other. If you can only have one, I guess it's the one you are more comfortable with. I am not a fan of Mitchell's wiring diagrams. I want to know where the connectors are. They have been slow in implementing connectors into the diagrams. Alldata uses reprints of the factory diagrams.
Alldata has parts and labor right on the same page as the repair. It's not in a separate module. But Alldata cannot do an estimate without the shop management package.
Alldata doesn't have an equivalent to "suretrack". That's not a prodemand feature I like to use but it has helped me a couple of times.
