Railworks 2 used to work really well for me. Trainsimulator2012, on the other hand, is a bit of a disappointment.
I can accept that my computer isn't up to the TSX game engine. With that on I can see the brilliant graphics but the frame rate is very slow.
What I find unacceptable is that legacy mode, with TSX off, is not as good as RW2 was.
Jerky graphics, occasionally the landscape disappears completely for a second or so. Also some of my downloaded upgrades don't work - like the more realistic acceleration and modified cab view for the Class 101 DMU. They don't even appear in the installer window.
Perhaps an update will solve these problems.