Only change it if you are somehow superstitious. I love #13 and all downstairs accommodations. The only time it really matters is if you have a true family in the Family Bedroom. On the Southwest Chief a couple of years ago, I had a downstairs room the farthest away from the FB, which on that run was occupied by a complete family that looked like a human representation of the old A&W Restaurants family (Papa, Mama, Teen [actually more like Tween], Baby [toddler]---plus an infant). I have no idea how they all slept in the room, but during waking hours they were constantly in and out of the room plus they kept the TA-SC/SCA running ragged with requests for this, that and the other thing. Then the infant cried frequently and the toddler screeched at times. If all that wasn't enough, the patriarch was often on his cell phone while one or more of the above events were going on. I would have found it more annoying being in #13 or the facing roomette, but it still wasn't as bad as other experiences.
The reason I like the downstairs rooms is that one can just pile on the train no matter what the stop and boom, you're in your room. No schlepping anything upstairs, no waiting for others with bags to schlep up or down the stairs, etc. Plus, if you use the luggage storage area and need to pull something out of stowed luggage, it's right there. Many times you can even drag your bag towards your room and finish your retrieval, thus not blocking the stairway. If you detrain at intermediate stops with no layover, it allows you to stage everything for a quick exit.
And, of course, if you like to get out and stretch at smoke stops, you're also right there (unless the car you're in is one in which the doors are not opened).