Very simply, do they lock from the outside?
When we go to the diner, or the lounge, or want to leave our bedroom for whatever reason, will we be able to lock it?
I've seen posts on AU about folks getting on board and having the SCA show them to their room, give them a brief orientation talk and take their Diner reservations. I've never seen anything said like, "and gave us our room key."
If we can't lock the room when we leave it for a while, I certainly wouldn't want to leave anything of value in there.
I have heard most people draw the curtain when they are out.
Last summer I accidently left my wallet in plain sight when I went to breakfast and it was still there along with everything inside when I got back. Luck of the draw, I would not try that again but just saying.
I've been riding Amtrak literally since May 1, 1971 with tens of thousands of miles in sleepers. My latest trip in October 2009 was between Tacoma, Los Angeles, New Orleans, Chicago, back to Tacoma via LA. On that alone I spent at least part of the day for 10 days rolling onboard in sleepers. The only trouble I had was someone broke into my truck and tried to steal it while it was parked at the station.
Yes, the doors only lock from the inside. I always draw the curtains and close the door when leaving my room, and make sure valuables are out of sight. I have NEVER had the slightest problem.
I have always traveled with expensive equipment, always with at least an SLR camera and lenses. Currently I travel with the SLR, a laptop computer, a 120 GB Zune. I sure don't lug it all to the diner.
Becaue I use a CPAP machine, I further wire up the room with a power strip. Since I have the strip anyway, it usually has a bunch of chargers plugged into it (cell phone, Zune, laptop), so even if the expensive stuff is not in plain view, it is clear I have something.
I have never, ever had a problem. Chill out, enjoy your trip, and worry about something real.