It's been said, and accurately so, that many have succeeded by carrying more weight than they needed to. Obviously, mental strength is more important than any gear and my hope for myself and any hiker is that they can summon this strength.
Unfortunately, many folks have also quit the AT because they were overwhelmed principally by the weight of their gear when they perhaps could have continued with better choices.
Knowing that, since you know the difference, why not lighten-up to give yourself the best odds? Basically, if you have the means ($$$), there are a lot of good suggestions here that would give you a good shot at being successful and hopefully make your time on the trail happier. Finishing the AT with a smile and standing upright is a lot better than with a grimmace and a broken back.
Like others have said, focus on the items that weigh the most. Although Granite Gear packs are very popular on the trail, so are those from ULA-Equipment, Six Moon Designs, and even Gossamer Gear or Mountain Laurel Designs to an extent. Consider swapping your bag to a lighter and warmer Western Mountaineering option such as the Highlite or even Caribou. Lose your pad and replace it with Closed Cell foam or a NeoAir. Lose your tent and replace it with a tarp (because you'll be able to stay in shelters much of the time, or if you need a tent, get something much lighter from Tarp Tent or Six Moon Designs. If you like hammocks, consider a Warbonnet Outdoors Blackbird or something from Hennessey Hammocks which are also popular on the AT. Consider a Ti-Tri Caldera stove from Titanium Goat as Esbit is far lighter and less of a fuss than alcohol or cannister stoves and the cone superheats your cup because it traps both the gases and flame to improve efficiency. It can also be used with alcohol or with natural sources which is something more stoves can't claim. For everything else, lose your redundancy. You don't need back-up after back up. Layer your clothing and use it with your sleeping system. Cut weight on things you'll rarely need - like rain gear. Get yourself a Dri-Ducks top and a ULA-Equipment rain skirt. Use trail runners and not boots (Inov-8's are popular on the forums, although you can find better support and cushioning from other mainstream shoe manufacturers).
Basically, all of this is pretty generic guidance you will find throughout the forums and in the book "Lightweight Backpacking and Camping" by Dr. Ryan Joran who runs this site/company. The reasons these things are stressed so frequently is because they work. Often it takes a lot of time to come to this realization, but fortunately you've stopped by because it is a topic in your mind and you're taking proactive steps earlier than reactive steps later. Basically, continue thinking about all your gear, look at all these suggestions, take a look at the book, and conquer the great AT!