I saw a demo at the Traffex exhibition in the UK a couple of years ago and subsequently had access to a demonstration copy.
It was fairly intuitive, I liked the ability to move a fully designed roundabout by the centre circle and the approach arms would automatically update to take into account the move. From a safety point of view I also liked the ability to get an estimate of vehicle speeds through the roundabout.
If the money was available we'd have probably invested in it. Having said that, a good junction designer should be able to get close to a workable design just using CAD and experience.
Yes, I have been doing design and analysis with CAD and spreadsheets. TORUS could be a real time saver, though. But, it has quite a steep price.
I was more curious about stability etc. Many Autocad add-ins can be prone to crashing. We have used Autoturn for quite a while, but we have an older version. It used to be stable, but for some reason is crashing frequently lately (and is only usable on an older version of Autocad).
AutoCAD Civil 3D has its own parametric 2D roundabout design tool. I think MicroStation V8i does, too. There's a 3rd-party vendor in the UK who has an application that takes off all the measurements and puts them into Arcady for analysis.
