I bought the Liber a month ago, and got to flip through the 'nomicon at session this week. Liber is excellent, but 'nomicon blew me away with the graphic presentation, the flavor text that was actually well-written (reminded me of Baron Munchausen, actually), and imaginiative creatures. I would not have considered running a late 19th century-flavored campaign before, but after looking through, I'm hyped to give it a try some time. It's not steampunk, it's not typical fantasy - it's imaginiative. I plan to buy it next week - and I'll be glad to have both books, as the Liber also has interesting monsters in it.