Oh, I have both the Lyman 49th and ABCs, they are anything BUT "advanced". I bought ABCs before I knew virtually anything at all and still found it basic enough to be virtually useless.
Not everyone learns the way I learn and the ABCs are great for a lot of people but it is most certainly anything but advanced.
The Lyman 49th is better but it's still just the basic reloading techniques and how-tos. Nothing advanced or especially insightful. Good manual, but not for advanced learning.