Pros

This is definitely the most complete disc spring software I have ever tried, I have used it in my applications (I am an engineer and I project sliding gates for ladles in steelplants) and its accuracy and being so easy to use are very useful for me

Cons

Maybe it is a little too expensive but I have seen the the new version is less expensive and anyway it costs less than the others.

Summary

I liked above all the possibility to design every kind of spring stack, above all stacks made with packets having a different number of springs. It is the only software I ever tried that allows this. The possibility of creating plots and 3D animations gave me the possibility.
Moreover its accuracy in calculating performances as deflections under loads and so on (especially using its new algo "equivalent spring") gave me what I really needed for my work, as I said I project sliding gates for ladles in steelplants by I hae used it also for other applications and I have definitely recommended it to my collegues.
I have also verified that what it is said on the site, in the CAD page, about the accuracy it is true, it gives me different values for the base angle and this is useful if you need to project a stack with packets having more than one spring.