Now that Empire is finally ready for release, I'd say it's worth the purchase.
It's all about trade in this game, you must get ports(if you don't have them), you must form trade agreements, and you must take trade outposts, do this and you almost win by default, you'll be swimming in money.
I find the other continents to be an annoying distraction, while simultaneously recognizing that this game had to be designed this way.
I'm almost ready to say I'm definitely purchasing Napoleon, I want to go back to the smaller scale of "just Europe".