In my case, I walked the Appalachian Trail first, then The Camino-the first being the Frances, then the VdlP.
Bryson's book was written as a spoof of the Appalachian Trail, to be entertaining and to sell books rather than to be informative. It only remotely resembles an AT through-hike and most readers who are familiar with one read the book with a certain amount of disdain. But it is good "humor", though, so long as one reads it in that light.
If you wish to find appropriate info on the AT, look to the forums on the 'net, just like you do here. When I walked the Appalachian Trail years ago there was a fantastic forum called whiteblaze.net that, I just discovered, seems to no longer exist. (If you find it, I am listed as 'highway' there, a name I was given many years ago). But, when I Googled "Appalachian Trail Forum" I did find this one which may have taken its place:
http://www.appalachiantrailservices.com/forum.html
I am sure there are more. These forums are full of like-minded souls who have "walked the walk", just like here, on this forum for The Camino, and are more than willing to supply you with any information about the AT that you desire. Just PM me and I will be only to happy to oblige as well.
Anyway, It is quite hard to compare the AT with the Camino as both are so vastly different with the only common denominator being that on both one walks along each, generally with a pack upon one's back. But, the AT is four times longer in distance, is many, many times harder to walk, is much less "comfortable", takes 5 or 6 times as much time to finish and forces one to generally carry about twice the pack weight, of 35-40 pounds or so, or better. There is in deed a vast difference between snuggling up inside one's sleeping bag upon the Camino on top of a soft cot with mattress, inside a heated albergue in a village somewhere along The Camino, after the luxury of a warm shower, than shivering along the AT, curled up inside that same sleeping bag, dirty, laying upon a thin backpacker's mat, upon a rough-hewn plank floor in a three-sided hut upon a mountain top in sub freezing weather with wind blown snowflakes piling up on top of you, all the while you are praying for dawn and the weak, warming rays of the sun to appear somewhere out of the east. Yep, there is a big difference between the two. But there are similarities as well.
The sense of family is just as strong along the AT as it is along the various Caminos. The friendships you develop along each remains just as strong until the finish and, oftentimes, for years thereafter. But there is a difference here as well. Only a tiny fraction of those who actually start the AT are successful in finishing it. It really is that brutal a trail. If you wish to finish, before starting, pile all your 'stuff' into three piles. The first pile has all your luxury items. The second pile has all your 'nice to have' items. The last pile has all your 'necessity' items. Then, toss out all of pile number one, all of pile number two and about one half of pile number three. Get your pack to about 30-35 pounds and you just might finish it at Mount Katahdin, if you go NOBO- or Springer if SOBO!
The same would apply to the Camino, too. Here, though, the pack weight is a paltry 20 pounds or less. keep it below 10 kilos and it will be immensely easier for you.
Ultreia e suseia