If you start as the Count of Holland, you can instantly create the Duchy of Holland immediately.
You're on the western fringe of the HRE, with a (in my games, at least) often rebellious Duchy of Lower Lorraine between you and the German King/Emperor. The weak Dutch counties are next to you (although they are vassals of that same oft-rebelling Duke of Lower Lorraine) while the French-oriented Duchy of Flanders is to your South.
I once got a claim on the Duchy of Flanders through a tourney-event. I declared war, got hopelessly trounced upon by the much more powerful Duchy of Flanders + French King, but suddenly good ol' Heinrich of Franken (who managed to keep the realm together for a change) came along, crushed Flanders, kicked the French out of Flanders and at the peace settlement -I- received the entire Duchy of Flanders. :rofl:
Needless to say, two generations down the line... I revolted against the Kingdom that made me great.
But yes... Playing as the Duchy of Holland is pretty fun, basically because you 'border' three different kingdoms and a fourth one (Denmark) isn't that far away. Much opportunities for a bold, strong leader.