Whilst I really enjoy the immersion of driving HUD-less, I generally end up leaving the top left part of the hud on because completely removing it means I sacrifice: -The reticle -The percentage indicators when I use the keyboard to manipulate the throttle, which especially makes using notchless power/brake controllers incredibly tedious without having to look down. -I can't see when I can close the doors on passenger trains. It's things like this that make me wish there would be an even more minimal HUD option with more fine tuned controls.