PaQ, In this cadegory, there is only one software - Silo, but we step much, much more futher with our app. Also vere is price tag differences and a lot of other factors.
About subd script, it uses Max's script, I disscused it with Max, before implement it, so everything is ok.
Our app also have bridge with 3Coat and I plane to make bridge with Keyshot. But this is just nice small additions to make life easer, the main feature of app is inovative, streamlined polygonal modelling workflow, that kind of workflow you do not meet in any other apps.