I love this demo, compared to the Fire Emblem demo I feel like I'm really getting a lot out of it. I agree with Eusis, I prefer the Airship to the Boat any day. In EOIII i never even bothered trying to do it because it was so frustrating.
Not much I can say, I'll definitely be picking this up. The music is just great, filling in my map with that music playing is just so peaceful. The skill system looks better, though I can't really judge it properly till later in the game when skills get all combo-y and synergy-y.