I agree wholeheartedly. I once hiked 13 miles on the Appalachian Trail going north from Newfound Gap. As I remember, after a feature called Charlie's Bunion the trail had a lot of ups and downs. Anyway, by the time I returned to the parking lot at Newfound Gap that same day, I could barely walk.
You are probably familiar with another beautiful area, Joyce Kilmer Memorial Forest just south of the Smokies near Lake Santeetah. I used to camp there at Horse Cove. Beautiful place, and it has some of the biggest trees on the East Coast.
I once hiked on the Appalachian Trail in New York and came across glacial scours on the bedrock. Pretty neat, but the area wasn't as pretty though as the main ridge of the Smokies north of Newfound Gap. Hard to beat that.
I have seen a lot of America and to me The Great Smokey Mountains National Park is the most beautiful place I have ever seen.