I have Railworks for a week , but i can not say that it is better than TRS.
You get more nice things out of the box ( in TRS you have to make them yourself or the community has to make them ); the sound is better, the physics are better ( but very far from perfect , and sometimes strange behavior ) .
Even if it is version 2 ( with a lot of updates ) it has still a lot of bugs.
The playability of Trainz is much better , esspecial for those that want to play with trains , and not just drive, drive, drive .
The route overview in Trainz is much better ( you can see the whole route and change levers )
In Trainz you can drive at night ; in Railworks also , but you see nothing ( the locs have headlights , but those doesnt emit light ; the environment is dark )
The documentation ( how to build routes , how to make content ) is non existant for some items .
the consequence of this , is that very little content is made by the community ( as far as there is a community )
You can buy some addon packs ( at steep prices ) , but i estimate the available content ( in comparition with trainz ) at 1 to 100 .