I bought RoN with T&P only a few days ago, so I'm pretty new to the game. I like the Conquer the World a lot! The bonus cards, the bonus resources, the wonders... it all comes together in a great mixture of TBS and RTS.
Something puzzles me though. I know I need armies to invade someone else's land. But are they any use when defending? I attacked regions with an enemy army in them as well as regions without armies, but I didn't seem to notice any difference. So are armies only good for attacking?