Years ago I played MSTS and loved the flight Scotsman. You could blow yourself up, over temp it and almost shut the engine down. https://showbox.tools/ Anything modern thats as realistic or better. TSW2 Spirit if steam seems ok.
Steam trains by Smokebox and Bossman Games have complex controls and take mastery to drive. Any Steam DLC with a Pro stamp will be more realistic to drive.
MSTS steam at least the original was very simplified. As stated above the Bossman stuff is very good, also Caledonia Works and Victory Works for TSC highly recommended. TSW2 Spirit Of Steam still has too many bugs to be worth a full price purchase, especially for such a short route. I personally am waiting to see if it gets fixed, there is additional DLC for locos etc. and a discount probably in the Xmas sale.
Good stuff on SteamSoundsSupreme as well. Loco enhancements, sounds, upgrades. They also sell a few loco's, but i think they are by other developers, like VW.
