My first reaction after a few hours are "SUPERB".
Napoleon is in my opinion what Empire should have been. Empire: Total War is overrated and too much about the broken siege maps. But Napoleon is underrated!
Napoleon is not perfect... but a great improvement. It's a complex and massive game. The sound is great, the look is great, the feel is great.
My first hours with this game have been great. I started playing the Napoleon campaign on Hard / Hard setting. It's still kind of easy but a lot of fun. And artillery are now a real deadly piece of steel. Moral meter is good add-on and the generals abilities and moral "aura". Hopefully we will see the near perfect Total War game some day. :)