Cliff, I just missed your last post as I was just adding a post... about iTrain.
iTrain is a very easy to use bit of software, my main reason for choosing it is that it runs on a Mac (as well as Windows and Linux) which I use. The user interface is very Mac friendly.
I believe the software has only been around for about three years, so is quite young compared to others. It is not currently as advanced as most of the other software out there (particularly Traincontroller from what I can see is much more advanced), but is very simple to use and set up. The automation is just by assigning a route to a train, there is no timetabling and the routes are quite basic at the moment. A route is defined from block to block with alternate blocks (eg when two station platforms are available) available either at random or in a chosen order and obviously waiting times are available where needed. This is version 1 of the software, version 2 is expected in a few months which we are told will include more advanced routing and many other improvements.
Scale speed of locos is measured between two of the sensors on the tracks, so each loco has a speed profile. Blocks are then defined with maximum, restricted and breaking speeds which are applied accordingly. Also trains can have a maximum speed applied (so a goods train for example can have it's maximum speed limited).
It will also control signaling which is my next project.
The developer is a chap in the Netherlands who is very responsive to suggestions. When I started using it I was the first person using my scale (1:19) (the scale is needed for speed measurements) and he had uploaded a Beta version for me with the new scale added as an option within 24 hours. There is also a forum and the develover and testers are very quick to answer queries.
That's a brief outline, whilst in it's present form it is quite basic I have found it hugely reliable (I ran four trains automatically for eight hours a couple of weeks ago) and it is under constant development. There is lots more information on the website
http://berros.eu/itrain/en/index.php