The book is what got our group interested in Anima in the first place. We're Warmachine players, and I have to say that Anima offers a nice change in playstyle from Warmachine. And, of course, the minis look sooooooo gooooood.
Funny, we're primarily Warmachine players, too. I've actually heard
good reviews for the most part from other Warmachine people that have played AT, and I'm really wanting to push this game. I might even see if I can get a game store up here to start re-carrying the stuff (they used to, but never reordered), and maybe try for the Free Agent thing.
It seems like there's something about Tactics that, at a basic level, really appeals to Warmachine/Hordes players. I don't know if it's the combat system, turn system, or something else, but it definitely has the that "thing" that will make it a success.
The ironic thing is that I originally picked up the game just planning on playing it with a couple friends, but now our entire Warmachine/Hordes group wants to play.

My LGS just started carrying Tactics last weekend, and right now I'm trying to get as many people to play as possible.