I just wrote this elsewhere.
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I have not tried CADrail, but of the other three I own, Atlas RR, XtraCAD, and 3rd PlanIt, I am now using XtraCAD,
I started with Atlas RR (free) and found it easy to learn, but clunky and since it limits you to Atlas track, restrictive. I designed a few layouts with it and when I decided to build found that the 4 x 8 I designed needed a 4.5 x 8 to work and hand to rebuild my benchwork.
I then went to XtraCAD (free) and after taking the 4-hour tutorial found it both easy and intuitive.
I like the idea of 3-D rendering and after asking a question like you are doing I paid $109 for 3rd PlanIt. It also has a 3-4 hour tutorial. However, this program I found to have a steep learning curve and is to put it bluntly, highly counter-intuitive. Since I paid for it, I kept working with it for over a year fighting with it the whole time. Then when helping some one with a layout design, I tried XtraCAD again and was amazed.
Things that took quite a few minutes to do in 3rd PlanIt, like building a yard, I can do in 20-30 seconds. But the basic stuff, like setting turnouts and joining track is so easy...
I basically, scrapped the $100 product, 3rd PlanIt and have returned to XtraCAD. The only thing it I miss is the 3d rendering, but everything else is so much more efficient with XtraCAD, that I'll do without.