My Wife, 17yr old Stepson and I recently took Amtrak from Tampa FL - Newark NJ, I've taken the train several times in the past, up and down the East Coast, and I love it. I find the seats pretty comfortable and I have a VERY bad back, 6 back operations and 2 neck operations in the past 12yrs. The seats recline pretty decently and have a foot rest, I was able to sleep for about 7hrs with no problem at all. I find the trip by train to be more relaxing than flying and the seats on the train are way more comfortable then the seats on the plane.
We have AAA and we got about $50 off the regular price of the train fare, it was really close on the price between flying and taking the train, I believe with our discount it was only about $30 more to take the train. They have a decent dining car on the train, we had breakfast and it was pretty good, French Toast, Bacon, coffee, that type of food. They also have a nice lounge car where you can get snacks, beer or a mixed drink, that type of stuff, on the regular Amtrak train you have to pay for the food but the prices weren't really high or anything, on The Auto Train the food is included in the price of your ticket. The train station is pretty much right in downtown Orlando so it is a little bit further to WDW than the airport is, not REALLY bad though, maybe 15 miles or so from Orlando to WDW. One piece of advice that we wish we had been aware of, bring a light jacket or blanket or something as the train was ice cold! It's like they had super power air condtioning or something! The train was about the exact same amount of time as driving would've been. Anyway, I enjoyed it, I had a good book and just relaxed and enjoyed looking at the scenery out the window, I prefer the train over flying...hope this helped.