How is it (in your opinion) compared to Tactics Ogre?
Sad to say that while I own Tactics Ogre on PSP, I haven't gotten around to playing it yet. What I can say is that it's still my benchmark for large scale map SRPGs, the Tarot aspect is fantastic, the difficulty is about on par with most Front Mission games, and it kicks the living crap out of stuff like Stella Deus.
The most visible difference, even without having played Tactics Ogre, is terrain. It's much less rigidly defined in Ogre Battle, and a bit more like Advance Wars, where it's basically flat terrain and what you're standing on (a forest, mountain, etc) has an impact, but doesn't really restrict movement like it does with grid-based SRPGs.