The BRP is a great ride. Sweeping vista's, smooth roads which curve on and on, lots of interesting things to stop and see from the Emerald mines around Little Switzerland, to the artsy shops and resturants of Blowing Rock to Civil War history out the butt in VA.
Although the Fall color was spectacular, if I was to do it again, I would not go in the fall. To many cagers and leaf peepers focusing more on the sights and not enough on their driving. We had several close calls. We did a similar trip in July and rode as far north as Ronoake, VA. We had the road almost to ourselves. That kind of surprised us as I had heard stories about how bad the traffic would be in the post July 4th weeks.
A couple of suggestions if you are going to do the trip. Make sure your ride has at least a 125mile range before going on reserve. Gas stops, especially at the south end are far and few between. Second, make sure to watch out for wildlife. My wife got hit in the head by a turkey which flew out of some bushes along the road. I had a near miss with a bear coming out of a blind corner.