Am I a man or am I a muppet? If I'm a muppet then I'm a very manly muppet!
The expansion makes the game twice as long. I played it once, and actually had fun. But other players in the game felt it took way too long. I traded my expansion away a while back. The core game is quite good. The expansion lowers it a notch (or two).
Kevin's right - buy Anno 1701: Das Brettspiel instead. It does what the expansion to 1503 wanted to do but failed to accomplish.