I've riden it twice and will be back again. The best plan for the parkway is not to really have a plan. Take your time, enjoy the scenery, and leave plenty of time for stops. Some of the walking trails to Mountain top views and water fall ravines are breath taking. If you enjoy the stops, 100 miles a day would be about average.....and take a good camera.
If your going thru Cincy, stop for a beer!