My main issue with the G6 would be volume and durability. I ate A LOT of food, easily 600-800ci for a 3-day load.
I did not hike the entire AT. Should have made it clear earlier that I did the southern 1/3. I didn't use a bivy, either, just a groundsheet. I used the shelters frequently because there was usually room and it allowed me to make an earlier and more efficient start. A few hours of social life was also nice, because I usually didn't see the same people more than once [mileage differences]. They also have this magnetic quality about them, despite the occasional irritating noises, stomping, snoring, mice, potheads, etc.
My thought was to carry the lightest shelter that I'm very competent with, mostly for back-up or for pushing the miles; my main shelters were those pre-built along the way. A poncho-tarp is a bit beyond my comfort range, but a small tarp is not. I guess it's balancing probabilities. The odds of a situation in which a shelter is full, there is a drastic rainstorm, there are no decent campsites, and you won't be able to dry out in a couple days... very slim. At the same time, I would have been comfortable using the 5x8 every day. There just wasn't much need to do so. I'd use the lightest items you'd be happy with day after day after day. I wouldn't want to carry around my 'heavy' Squall for 3 months, but I have friends who wouldn't want to do the daily fiddling and re-inventing that a small tarp needs. It's all good.
As for Wanderlust, the owner has developed a reputation for a couple things 1] a well-made and dependable product 2] disappearing from the face of the earth, not answering phone calls, delivering products after agonizing months without contact, and in some cases, he is alleged to have failed to deliver after payment. The forums on www.backpacker.net have lots of anecdotes. Buyer beware.