We did it! We are going from Raleigh, NC to Orlando, FL. We did the 32,000 pts for getting the Amtrak card. We got the 2 roomettes (there are 4 of us) and it cost us 30,000 pts (15,000 for each roomette)one way. We paid for our tickets to return home in coach. It was great because those pts included the train tickets AND breakfast for us. So our round trip cost was $140.40 for all 4 of us.
Editted to note that we are taking the Silver Star...not sure if that is different from the autotrain. Call the Rewards center...I did. They are so nice and very helpful! I had to wait on hold for quite a while when I called, but it was worth it.