Dirt versus sand riding, what is more fun on a dirt bike?

I have been riding dirt bikes for 5 years and quads for much longer than that but I have never once ridden in the dirt with a dirt bike. I have only ridden sand before and I am kind of curious, is dirt a lot more fun than sand? I have a 2004 yz 250 and was thinking about buying a dirt tire for it but wasn't sure. I live right next to the Pismo dunes and the closest dirt place is about an hour away. Is it worth it?