Yep, I have and have read them both. Both are great books and incredible resources for WHFRP2.
Liber Chaotica is a compliation of the previous 4 Liber Chaotica tomes (Khorne, Nurgle, Slannesh, and Tzeench), as well as having a 5th extra chapter in it on Chaos undivided. No game stats at all, but great background material. My only complaint is some of the notes scrawled in the book in red or brown ink are somewhat hard to read (supposedly the scribblings of the madman who wrote the book).
Sigmar's Heirs is a great resource, that is invaluable for running a WHFRP2 game. I've been using mine for about 3 months, and I can't imagine not having it. TONS of great background and factual info, with few inconsistencies in the data. There are some editing typos, but I don't care about those. I've found the people who nitpick on editing typos usually have nothing better to do than gripe anyway, and take themselves far too seriously- so definitely take their criticism of the book with a 5 lb chunk of salt.
That said, Old World Armory has some good info in it, but the monetary system is badly messed up- one of the few times an editing gaffe made a book much less useful.