No worries, I'm glad I was able to offer some insight.
DTG's Train Simulator is probably worth another look graphics-wise.
I just retired my old Acer Aspire compact desktop I bought from Wal Mart five or six years ago, and running Train Simulator on that was hit or miss. It only had like 4GB of RAM, an AMD processor, and a lower-end Nvidia graphics card, so I either had to run the game with graphics so low that even the effect of headlights shining on the ground didn't work, or the frame rate would be so bad that one second in game time would be doubled or tripled in real time.
Last week I bought a Lenovo Thinkcentre from Best Buy with 8GB of DDR4 RAM, an Intel 6th-gen i5 processor, and a Nvidia GeForce GT 730 graphics card, and the difference is HUGE. The graphics aren't maxed out, but they look pretty good at their default settings detected for my machine. It's nice actually being able to drive at night now too lol.
One little feature I enjoy is the rain and snow accumulating on the windshield, giving the wipers an actual purpose. People still tend to appear and reappear on platforms, but to me that's easy to ignore. I spend most of my time in the cab and only stick my head out to spot on station platforms or perform switching moves. If I have to reverse a freight drag or passenger consist I will cheat and use the rear overhead camera in lieu of a spotter.
The same company is producing a 'next-gen' simulator called Train-Sim World (there's a thread in this forum discussing it with a YouTube video showcasing it). The graphics are displayed using the Unreal engine, and in my opinion look about as realistic as you can get for the time-being. It'll be interesting to see the game as it develops, and it's probably more of what you're looking for in a sim.
"That sapling that once grew just south of Wassaic may be long gone, and the Harlem Line’s appearance may have changed over the years, but for decades to come, I can count on it continuing to provide me with funny recollections"