My wife says the AT is the most comfy pillion seat she has had so far. She likes the width, seat firmness, leg room and space in which to change her position. Admittedly, there have not been any big tourers in our stable ever, but it does trump the Triumph Tiger 1050 we had for a number of years and that was an excellent all day mile muncher. The only negative may be the amount of preload at your disposal, which was even more of an issue on the 1050 btw.
My wife mloves the bike as well.
Had a few decent trips and she has no problems. Actually prefers it to our last bike a Pan European ST1300 - says the ride is smoother.
We always ride with a top box with the passenger pad on it - again a choice she prefers as she can rest back onto it.
Need to break every 1 1/2 - 2 hours to for overall relaxed and comfortable journey.