We are returning for our 9th WDW trip. We have travelled both coach and sleepers.
The Bathrooms are on the lower level. The staircase is extremely narrow and the train is rocking. I always walk infront of my DC. There are 4 types of Bathrooms on the the Autotrain in Coach. the first on is basic narrow bathroom. Not much room for 2. It is doable but tight. The 2nd one is a handicap one that allows the wheelchair to go in but we don't use that one.
The 3rd one is a dressing room one. When u enter there is a bench for sitting to change your clothing and it has a small bathroom attached. I find this one is the best because it is a bit roomier and there is a spot for DC to sit while mom/dad can use it too. the last one (which is at the end of the hallway) has a large vanity - mirror and stools with a small bathroom attached. As you can tell we were bored one trip and explored all the bathroom options on the train!
The AT has been sold out the last few years in August. We travel beginning and mid August - alternating each year and it has been a full train.
We have never had seats on the lower level in Coach- always upstairs. We did have sleepers lower level last june and the bathroom doors where never closed all the way when not being used and the doors banged all night.-- that got annoying after a while.
Let me know if you have any other ?'s. WE have traveled with 5 DC with ages ranging from 1 to 18.