We stayed on loop I, near the AT. Sites are crowded together. It was pretty noisy the time we we there, mostly kids. Getting level never happened. In hindsight, we should have picked a pull thru.
We were given a nice welcome and our campsite was switched to a more level one without a problem. We took 3 days to drive the skyline in our truck camper camping in the park. We attended a night time talk and enjoyed seeing and hearing the love a ranger expressed for the parks in a piece he wrote for the centennial celebration. His passion for nature was most moving. This is a busy area in the midst of nowhere. School buses brought in kids for learning. We watched 3 films in the visitor center--all added to our enjoyment and learning. Get a passport stamp at each visitor center. Fall colors were lovely about 1/3 into change.
This was my first national park so I waited to review until I had some comparisons. All the sites are large and feel private, beautiful trees, what you want in a park. Step out the back end right onto the Appalachian Trail, which is awesome. You can get as much or as little immersion as you like. The bathrooms are rustic, showers and laundry a distance--plus, not as nice as most other parks. Visited in May, 2018.
There is a serious problem with at least Garmin GPSs guiding you to this campground. You may end up at a dead end road with nowhere to turn around. There is a problem with map data that makes the gated fire road look like a valid route. Neighbors up there say it happens all the time.