I too have done the spices in the dough.
Not since finding this site, tempted too.
I have found that I put the spices in the dough to make the dough taste less like bread. That was before the help and information that I got from the posts here.
Now that my dough tastes like pizza dough, I may revisit adding some spices to the dough.
Still want to try a couple more recipes and variations before doing that.
Definately adds to the flavor of the pizza