I was given the Monstrous Arcanum book as a birthday gift recently and firstly I have to say what a completely gorgeous book it is. I've owned plenty of minis from FW before, but never one of their books, and it has completely bowled me over. For only a £7 premium to the army books (which I thought were very nice before) this thing makes them look completely amateurish.
Anyway, that aside, I've been reading the various binding scrolls and really like the look of some of the monsters. As a LM player I can't wait for the Dread Saurian to come out - (a) because the mini should be incredible and (b) because it looks hilariously OP to use in games of SoM. An ambushing Ethereal monster killer? Sounds like my cup of tea.
As for most disappointing - I think the Colossal Squig looks like a complete waste of time. Am I missing something or is this thing twice as expensive as a mangler but half as good? Shame, as the model is fantastic.
So - what are your experiences with the monsters from the arcanum book? Any hidden gems, underrated gribblies or some complete waste of points? Any models you're particularly looking forward to?