Each simulator has its flaws.
Okay, since I'm not a user of railworks (so I'm not really in a position about how good or bad railworks is), I will just link you to a site I found that talks about the bad points about railworks
http://www.uktrainsim.com/index2.php?form_reader=whynotrailworks
But, yeah, as another user on this forum pointed out.
These threads are always fun.....
played both and trainz wins really if for nothing else the fact that I dont have to pay for every piece of grass I want to place on the route.....
I still do miss things about RS like the lighting, some aspect of the physics like that if I made a 5 mph coupling the cars would react appropriately and definitely being able to read the switchpoints without an indicator, DOPPLER EFFECT. Definitely a few things from RS that id love to see in TRS but TRS is still the better sim overall.
Trainz has its flaws as well, such as artifical lighting (This is a thread which I posted on which gives some insight into that problem
http://forums.auran.com/trainz/showthread.php?t=55694), The doppler effect has been mentioned as a problem.
And there are some unsaid problems, such as theere's no notification for the trainz I chat once you open it up, and the trianz in-game browser doesn't open up any other sites except the auran's ones as well as the de-railment realism in TS2006 (I am not sure if these have been fixed since then).
But... In my opinion, I think the main problems I don't like which trainz have over, is the AI, as in when you try to play the game, you can't assign more comamnds to the driver while playing, similer to trainz's senareos.
But, some people just value some problems with games over others, and just live with the train sim, such as everyone that has played with trainz has managed to live without good graphics, the doopler effect, realistic artifical trackside lighting and more, and still have a lot of fun, it's things that would be nice to have, but could live witohut.
I guess it's only an individual that only applies "priority" or "amount of importance" that these game have that makes them want to switch or stick with a train simualtor, it's only a matter of opinion.
I think that's my only insight into comparing railworks with trainz.
What makes a good game is the individual's choice by comparing what he dislikes/likes more out of the avalable advantages/disadvantages of a game that a company has made, to another companie's game that's in a similer/the same playing field.
In layman's terms, it's all about opinion that makes a game good or bad. And it is many of the similer opinions that makes profit for the company.
To be honest, I haven't said which simulator is "way ahead" like other people have, because it's just the matter of opinion.
P.S. If you set aside a game's flaws, it can be a good game, but you have to tolerate those flaws.
P.P.S MSTS still lives with this principle, even though it's 10 years old and the company isn't continuing on it.