Ancient Enemies is one of the must have very soon book, like Mortal remains. The core book is to vague in how stuff are, some like it like that and ac tually think Ctech is better by only using core and vade mecum, good for them. me I like the add ons very much.
Some think the dhoanoids are a bit to generic evil, but that suits the faction, its hard not to see them as the bad guy.
Eldritch gets a very nice overview, and must say that I love the imagry of their inner sanctums. Metamorphosis is good, though the "roleplaying" requierments is a bit over the top with the exp cost, but it seems fun, when that time comes I shal see what my players think of it.