Hi there,
I'm just visiting MRF after something like a two year absence (partly brought on by a house move)...
But anyway - have you considered Rail Simulator? It's developed by the original MS Train Simulator team (Kuju), but is a much more modern product. Doesn't have the same quantity of content yet, but it's getting there.
It has its detractors, I know, but is certainly an advance on MSTS, in my opinion.
Worth a look, if you're interested...
Best wishes,
Paxman