I really have no recommendation as far as rooms on upper level vs. lower level and have had both. Here's a car floor plan in case you haven't seen one:
Upper level rooms have the advantages of:
• Being able to see things from higher up with views not as readily blocked by rolling stock on adjacent tracks or cuts through the terrain
• Closer to the coffee pot
• No need to traverse the stairs getting to/from the diner or sightseer lounge cars
• Less eyestrain looking out the windows as the scenery doesn't seen to whiz by so fast
Lower level rooms have the advantages of:
• Better views of adjacent trackwork, boxcar graffiti, other things down low to the ground
• Two more common use toilets to choose from (only one of them upstairs)
• Easier access to the shower room
• Easier access to any carry-on luggage stored on the racks shown above.
• Much less foot traffic in the short hallways that are dead ends
• Outsides of windows can be cleaned for better viewing & photos
• Easier to hear the various sounds made by the wheels when going over turnouts, bridges, rail joints (occasionally)
• A very narrow enclosed closet on the right side of the entry door.
The main thing I don't like about upper lever rooms is its single commode. It doesn't happen too often, but its condition sometimes makes me wonder what kind of potty training some people got. That's less of a problem with three to pick from downstairs. And I'm by no means a hoity-toity bathroom connoisseur. I've got two of 'em and here's the second one:
But, one person's likes are another person's dreaded fears. Some hate the potty in a Viewliner Roomette, but I think it's pretty neat myself.