It's a pretty road to be sure; was just there a few days ago. The southern part is curvier and hillier (with more tunnels) than the northern part; I would start from the GSM National Park if possible.
The parkway is relatively slow going. Get the free map brochure and the free newsprint activity guide at an info station. There are a great many places to go on hikes of all different degrees of difficulty. Pack at least a lunch each day; restaurants are not at all plentiful, even along intersecting roads.
If the weather is rainy or foggy, the parkway is a lot less special than if it's a nice clear day.
