I've hiked a lot of the GSMNP in the past so this time I decided to hike the entire park in one trip. We started at Fontana Dam and hiked through to Carvers Gap on the AT. The entire trip was 72 miles and took 6 days. This trail was the first leg and took 3 days at which time we caught a ride into Gatlinburg to resupply.
Doing this part of the AT from south to north means a lot of up hill climbing, some of it quite challenging, but the views are worth it a million times over. We did the hike in late Winter and had very cold temps (10* F) with lots of snow and ice. I wish we had gotten cramp-on's for our boots because that would have helped with the ice conditions. That time of year the trail is prone to freeze/thaw conditions each day which means you're walking in slush during the day and slippery ice in late day and night.
My favorite summit was Rocky Top on Thunderhead Mountain. It's a small rocky area that gives you amazing 360* views. The Shuckstack lookout tower just a few miles north of Fontana Dam on the AT is worth the time to check out too.
I would have rated this hike 5 stars if the park would let you tent camp at the shelters or anywhere on the AT but they don't, so I didn't.