I like to have the manuals for the components I plan to use. If am using Hornady bullets, I want Hornady data. Same for Nosler, etc. I agree that the Lyman is the best all round.
There are so many new components that it is good to keep up with new manuals. To use an example from shotshell reloading, I used the same load for 25 years, Same hulls, wads, powder. I go to buy a fresh supply and my favorite wad and powder have been discontinued. I had to start from scratch with new components. I even had to buy a new powder bushing.