I have the ABC's and the Lyman 49th. I am a new reloader, so finding a load is important to me for safety reasons. Well, hate to tell you but I have not found one single load that matched the materials I have. When I go to Cabelas, I sometimes look at ALL the books and never find the exact load.
So, I think if at all possible you should have as many as you can, unless you only buy a certain powder/projectile and you have a load for it.